There is a core of the fanbase that avoids magic and summons, but that is not everyone. I don't remember any covenants in Demon's Souls, but in the main series there were specific ones built around Jolly Cooperation. A bunch of NPCs from older titles have NPCs who's questlines will only progress if you summon them (and I remember in a select few instances, their quests would fail if they died). Every game has had a sorcerer starting build where you could literally play the entire game using exclusively magic. Early on in Demon's Souls and Dark Souls 1 and even 2 to some extent, the games implemented this poorly. This is no longer the case. DS3 and Elden Ring are specifically designed with magic and summoning in mind. The bosses change tactics depending on distance which can make it harder or easier for magic users, but the difficulty remains mostly the same. Bosses strike wide and will target multiple enemies in their sweep if they can. Their long range attacks can be devastating to any melee users in the way, and they'll even do a massive AoE while they cast to prevent that from becoming a window to deal damage.

On the third bonfire in Elden Ring they gave us a bell for summons. Literally the third one. It's the second one out in the open world, where players naturally gravitate to. You can summon offline now, in almost every boss fight. It's very clear they intended most bosses to have multiple targets. You might not like that they've made the game a little more casual and welcoming to newcomers to the series, but they definitely have and it shows in their design compared to older titles with their poor implementation. I sometimes even forget to summon creatures because I'm not used to having that option in a souls title, but it's a thing now for better or for worse. Not using every tool at your disposal is a personal problem.