Exactly this is what I feel like Elden Ring has been missing from the start: factions with rewards to encourage multiplayer engagement. I even miss Aldrich invasions and being a mound maker. Half the invaders in Elden Ring play like mound makers anyways and attack everything indiscriminately... may as well get some shackles for it.
That and the removal of the ember/humanity requirement made it less likely that people would be exposed to invasions. I remember beating bosses, forgetting I was ember-ed, and run into an invader at the worst/best possible moment. I know that some people hated being forced into PVP, but it got the blood flowing and made every play-through feel just a little unique. It added character to the world, made it feel alive.
Edit: What would some interesting factions be for Elden ring that would be lore friendly? I like the idea of maybe a SOTE invasion class being fire knights. In hindsight they could have locked some of the spells and weapon arts behind this instead of the NPC invaders. The bloody fingers and recusant fingers were clearly based on some of the invasion factions in previous games, would have been cool to see at least one of those have rewards based on invasion success/spoils. Golden order would seem to be the closest analogue to the Warriors of Sunlight, and has a handful of relevant spells and weapons that could have been chases. Maybe a faction for Those Who Live in Death that could have been like the Gravelord Servents or something?
I really like that line of thought.