The Chalice Dungeons aspect of Bloodborne was one that a lot of people didn't like. I'd spend all day on Sunday (well, more than that...) co-opping the chalice dungeons at random or trying to find a Boss to hang out at and ring my little bell. One build named Rom Killer ended up being a One Reborn "specialist".
Near/far summoning means to me that more dungeons and more dragons = more summoning pools and co-op. Lots of hours helping others improves your own skills and gets you runes and Rune Arcs to use (5 bonus points on every Stat until you die is the first). Dragon fights are great fun co-op! If you want to level up, co-op with others. You can't lose your own runes doing so. At 500,000+ a level, regular farming bites. A couple of co-ops and I'm over 1,000,000.
Wondrous Physick I didn't suss out for months. Depending on the build and which I've collected, a quick chug before a Boss can, say, increase Strength and Dex by 10 points for a few minutes. Well worth it. At first I used it an extra Heal flask.
I won't start on pots, perfumes, bairns, grease, Golden Vow (15% buff to attack and defence!) and the like. You can't really use them at will unless you can trade/dupe materials with a friend.
In Elden Ring you cant get Invaded solo, so the Multiplayer aspect isn't as obvuious and sudden as getting Invaded in Demon's and having your World Tendency shredded by some @#$% who can kill anything nude with a club. Especially me. First time was "Wtf was that? Someone deliberately Invaded my game to ruin it when the game is hard enough ...? How do I kill them?!?" They trounced me often, but not so much these days.
I have never Invaded in any FROM game until ER for Varre's Quest. I find a cliff to jump off, or wave and offer a quick back-stab. I co-op all the time.
EDIT: As I said, there are so many different ways of playing these things. Some of our "Jolly Co-op" group start Invading 'coz they are bored. One who is in NG7 at level 11 with +3 regular weapons and finished the DLC (not me!) is incredible, but the regular game is too easy without imposing limits on themsleves. I just help folk where I can, often as a Hunter as well.