Lots of really great posts in this thread. I see the need for co-ops, for 8-man, and I am surprised 6-man isn't getting much love here. I only saw one mention of it and Texas plays it, I think Nebraska does too.
A lot of states have 6-man teams. But not as many have state sanctioned 6-man classifications. Usually, it's 'renegade' programs that aren't members of their state's association.
Right now, the best I can tell:
Washington (unofficial), Oregon, California (unofficial), New Mexico, Colorado, Wyoming, Montana, North Dakota (unofficial), Nebraska, Kansas, Texas, and Missouri (unofficial).
Generally, you're going to need a few things to make six-man work. Very small schools with a lot of distance between schools. The situation where co-ops generally can't work just due to the ungodly travel times for things as simple as practices.
But co-ops do happen at the 6-man level. In Montana, a school I saw was Grass Range/Winnett. Grass Range has 18 students in high school (that's all four grades, boys and girls), while Winnett has 19 students. Winnett is the only town in Petroleum County, which has just 496 people.
Due to low numbers, Grass Range and Winnett joined with a 3-team co-op among Denton, Geyser, and Stanford. Denton has 7 students. Geyser has 12. And Stanford has 26. The MHSA let them combine as a five-team co-op to play 6-man football. It's 114 miles from Geyser, Montana to Winnett, Montana. And they were playing and practicing as one team. They did this for two years. Before Grass Range and Winnett finally had to co-op with the 'big school' in the area: Fergus High School in Lewistown (in Fergus County that sits in the middle of the 5 teams that formed the co-op). With 336 students, this put Grass Range and Winnett players into 11-man football and essentially lost their identities as schools.
And for reference, 8-man is much more common. It's in Montana, Idaho, Oregon, Washington, Nevada, Utah, New Mexico, Colorado, Oklahoma, Kansas, Nebraska, Iowa, Missouri, Wisconsin, Michigan, Ohio, New York, Pennsylvania and Maine. Some are unofficial, many out west are official and have their own state playoffs under the state association. Some southeastern private schools play 6 or 8 man. but usually outside a state association and with far less 'official' status.
Notably missing is North Dakota, South Dakota, Minnesota, and Wyoming. Who play 9-man football instead of 8-man football. Interesting that when Wyoming added a level between 6 and 11 man, they went with 9-man instead of 8-man which Montana, Idaho, Utah (added after), Colorado, and Nebraska all play bordering them. While just South Dakota played 9-man.
I think Ohio would benefit from 6-man because it would cheaper to institute if a school is starting up it's team from scratch. Plus, there are many schools struggling to field teams. Including larger schools like those in the Cleveland Senate. 6-man would accommodate an even smaller roster size. As Queencitybuckeye said, isn't it all about the chance to play? I think teams would be delighted to win an "unofficial" OHSFCA championship, unless &/or until the OHSAA does something about these 3 situations.
For six-man, the primary expense to 'start a team' is going to be pads, helmets, and erecting permanent goal posts. I've seen very small schools without any type of stadium whatsoever. Fans simply pull up in their cars to surround the field, or just stand a few yards from the sideline and move like a flock of birds as the line of scrimmage moves up or down the field.
So, a stadium, scoreboard, etc isn't entirely necessarily right off the bat if not needed. Alexander, ND used a small utility trailer to act as a press box with the roof of a bus for the announcer's view of the field. Waterloo, in Ohio, used a flatbed trailer when their stadium was demolished after being condemned and a new one hadn't been rebuilt yet during the covid season.
As for the suggestion about larger schools playing. This is an issue that the smallest of small schools do have with participation. The point of going to 6-man or even 8-man is lack of absolute numbers. At the end of the day, a bigger school with less interest does still have a ton of potential players if or when that interest increases. And you can't just easily hop back and forth between rulesets. Especially from 6-man to 11-man or vice versa.
A poster above touched on the Ohio Valley and it's population loss. The 10 counties losing population faster than the other 78 are all on the shore of the Ohio River or near it. SEO. Seems to be very fertile ground for the introduction of any/all the three options, co-op, 8-man, 6-man. I think the Senate should look at these as well. probably almost everyone but Glenville's successful program would benefit from a switch. (Assuming the Senate didn't say all or none switch.)
If and when OHSAA makes 8-man a state tournament eligible classification, I think you'll see more schools opt for it. Or, rather, if they're caught up in some enrollment cutoff they won't fight their placement in 8-man. It's the same issue with mercy rules. If up to the coaches, most would never okay the mercy rule be used in a game of theirs, even if staring down a 50-0 halftime deficit. However, once the 30-point rule was enacted, far fewer coaches would actively fight against their games having a running clock in them. Be it favoring it or against it.
Schools like Beallsville, Corbin Miller, Millersport, Southington Chalker (going next year), Mathews, Windham, Richmond Heights, St Thomas Aquinas, etc. Could all look favorably at 8-man but wouldn't want to be the ones to have to make the decision themselves at the risk of displeasing their communities.