I don't edit on mobile, so can't help there, but for PC the easiest option is to stick with capcut and just use a VPN.
if you want to change platforms, there are a lot out there. Clipchamp is easy to us and is a microsoft product, but its also not necessarily robust. if they want something robust with a bit of learning curve, the free version of DaVinci Resolve will work. The drawback is that they will have to learn to do a lot of the effects manually. There's not a bunch of text templates and such.
Kosmic looks interesting, but they are still in beta and pricing looks higher than i'd want to pay.
The closest alternative as far as functionality as well as look/feel is Filmora.
lots of discussion on reddit. here's a decent thread:
https://www.reddit.com/r/CapCut/comments/1hus6te/i_tried_capcut_alternatives_and_here_are_my/