I live in Mammoth Lakes, CA and LOVE it. Have two kids, ages 9 and 6. They get $35 season passes through their school and participate in "Ski PE" where they bus up to the mountain twice a week to ski, as part of a school program. Currently they're doing a "Bike Squad" program through the town rec department where they're picked up right after school and ride their bikes around the area for a couple of hours. We're also involved in soccer and they have practices and games at a beautiful park called Shady Rest. In the summer there are tons of camps and endless hikes and swimming. They are absolutely thriving.
I can be out my door and on a lift in 15 minutes or less of easy town driving or public transport, depending on which lodge I choose. The snow is pretty consistent, and the season can be looooonnng (last season, for example!)
It's a great community. I have so many friends because the area self selects for people with very similar interests and views. It's a fairly progressive town and has voted Blue for as long as I've lived here (15 years). California is also great in that regard of course.
There's a wonderful local hospital for most of your needs (mammothhospital.org). There's a fantastic library, a community college, arts council, breweries and distilleries, free live music every weekend in the summer, free local transit, and absolutely stunning views. I have to pinch myself every time I go grocery shopping since the mountains behind Vons are so gorgeous!
There's two local airports, one right near Mammoth (MMH) and one in Bishop (BIH). It's also not too bad of a drive to go up to Reno or down to LA for more options. For getting around town, we hardly drive. We can walk, bike, or get the free bus almost anywhere.
I'm not a huge shopper so can easily get what I need through the occasional Target or Amazon online order. There's a robust parent's network for hand-me-down clothing and gear, plus a few thrift stores in town.
I work from home, and have 1gig internet service.
The two negatives: housing prices, and forest fires. The town is building a bunch of new affordable housing (The Parcel), so once that comes online (later this year, I think) it should alleviate rental prices. Buying a place is going to be harder; basic condos are half a million. The market is definitely cooling off though after the Covid frenzy.
Like others said, forest fires are sadly just going to be something to deal with anywhere out west (.... and out east, apparently, after this last summer). We have air filters, and are going to get heat pumps (despite the name, they also cool) so when the air is bad we can flick both on and be comfortable inside. There is active management of the "donut" of trees surrounding the town with thinning and prescribed burns. It's not foolproof, but they're paying attention.
Let me know if you have any questions and good luck!