though males and females develop differently during puberty, should we just have co-ed sports?

They have co-ed sports in colleges and universities and it works fine.

The goal of co-ed sports is the fun derived from participation, not competition.

That said, I have no problem with trans athletes competing in regular sports.

I don't because they have already been competing for decades and it hasn't been an issue.

These questions should be left for the organizations that sponsor and regulate sports competitions.  If kids (or adults) want to get together on their own and play a game, it's up to them who can play and what rules will apply.  They'll make their own allowances for different ability levels among players, so players can be of any age, size, strength, or speed.

When it comes to organized leagues or federations, there is always a board or commission that sets the rules - and they will dictate such things as age or gender limitations (or they'll specify some other sort of standards on performance or ability-level).

Doing so would be to ignore the obvious physical differences. Where strength or height was helpful, men would always win.

thats up to the schools