The device should be absolutely caching the most recently used apps, yes. Force closing is unnecessary, but I manage my apps on my phone not because I want to close background apps, but because I want to keep certain apps running (I don't care about steam or my email or messenger, etc, they open fast; the browser is slow and I want that to stay loaded).
Unfortunately, I can dismiss/force-close all apps on my phone, open Firefox, switch to the home screen--and when I switch back it has to start up again fresh about 25% of the time.
The only reliable way I've found to use termux (as an ssh client, not anything high-resource) and Firefox at the same time is to use multi window, dragging termux out of the way of the keyboard every time I switch, as Firefox will regularly need to be reloaded otherwise; if I'm on certain heavy or lazy-loading websites or using a link with a hash in it, it'll then also lose my scroll position. This is particularly frustrating when I ssh into minimized containers with no command completion or man pages.
The only reliable way I've found to use termux (as an ssh client, not anything high-resource) and Firefox at the same time is to use multi window, dragging termux out of the way of the keyboard every time I switch, as Firefox will regularly need to be reloaded otherwise; if I'm on certain heavy or lazy-loading websites or using a link with a hash in it, it'll then also lose my scroll position. This is particularly frustrating when I ssh into minimized containers with no command completion or man pages.