No, you really want them to board first.
For the last year, up until last month, I was barely able to walk. I still had to fly for work. I boarded flights with the kids and anyone else that needed help.
The parent doesn't just stow their stuff and sit down. They stow the kids bags, get the kids to sit down, shut up, buckles on, no you can't go to the bathroom, blah, blah, blah.
For me, it took me about 4x as long just to get down the airway. A guy barely walking down the ramp with passengers walking normal speed definitely held up the flow, no matter how much room I tried to leave. I still got held up by the parents with kids, and I didn't care. I'd just sit on the nearest armrest until they were done.
You don't want me, or the parents with kids slowing you down. People are assholes enough boarding planes.
If you wait for them to board last, now you'll have parents trying to stow bags in the last few spots (if there are any), trying to get the kids in their seats at the same time, and having the kid(s) climbing over other passengers.
For me, barely able to walk, if I had to take the window seat, that would mean everyone in the other seat(s) would have to move. Walking on a cane, I wasn't able to just squeeze by anyone, especially if there were no good seats available. It was still hard just to get *to* the window seat.
And before any of you complain, since surgery I can walk fine. The cane is retired at least for another 30 years.