5e (and 5.5) in general is not a perfect game by any means, but it is a compromise game between many things D&D has been and can be, the "everyone's second favorite edition" school of design. I find 5.5 more or less a straight downgrade from original 5e and think, long term WotC's design philosophy is getting less appealing to me, and lacks any sort of clear direction, which may well ultimately get them usurped from their throne by some other game. However, the usurper has not yet come (or has not yet reached critical mass in players). At the moment it's still the big game, and that is a selling point, because it means that unless you live in some remote village, you will be able to find multiple 5e games in your area, and probably a group you vibe with, or create your own group and find people who have played before. It's not my perfect game, and got less perfect with the 5.5 update, but I enjoy it and always have plenty of people to play it with.
I typically run and play 5e games with minimal tech (I find it easier to organize notes on my laptop and often find it faster to look up spells and stat blocks with google than to bust out the books, but that's all mostly a function of making the most of limited table space). Meanwhile virtually everyone I play with at the moment seems to be D&D Beyond addicts, but I've never touched that crap (it tends to be a crutch for people to not actually understand how their character mechanics work). There is absolutely nothing about 5e or 5.5e that mandates getting locked into a subscription model. Maybe the next edition will foist such things on us, but currently the talk about subscription models seems to mostly be to impress clueless shareholders. Except in the sense that some secondary official materials are only available as pdfs there is nothing mandatory about tech (and I'd say these days you need to be willing to use a pdf to get some materials in most rpgs, at least if you miss their limited print runs).
I'm going to be running 5e at a summer arts camp for like 6 weeks this Summer with nothing but books, dice, pencils, paper, and imaginations, in a tent out in a field without even a power outlet, as I have several Summers before. It's very doable. No tech required (other than printing out a fat stack of character sheets at an office supply store).
All that said, if you're on the fence about 5e/5.5 I'd say the first step is to figure out what games someone in your area is running. The group matters more than the game, which is why I'm still in my Daggerheart group despite that game seeming to be built almost exclusively of design choices I hate.
I've seen it mentioned many a time over that even in the early lower levels, PCs become indestructible with a focus being on moving through the story over dungeon crawling. Do DMs have house rules that balance some of this out, or is it unfounded conjecture from the internet in itself?
It's not unfounded, but PCs are only "indestructable" compared to PCs in some other games. Character death only commonly happens in carefully balanced encounters through about level 3, but if a table wants to play things deadly it's certainly possible at all levels, and the dice can always just really go against you, and often do for someone before the campaign is done. I don't know, for me it doesn't really matter if my character dies, it matters if I think they might die, and I personally get enough of that in 5e, with a suitably skilled DM at least (encounters can always be made deadlier). Most of the adventuring party in Lord of the Rings made it to the end, and that's a pretty good fantasy adventure story; generally a story where none of the original participants see the end doesn't make for much of a story.
But yeah, if you want a game where PCs die all the time and the focus is on dungeon crawling specifically, something in the OSR is probably more your cup of tea. There's a good chance something in that vein can be found near you.
