So there's this one guy I forgot his username who claims people have inflated ELO by 400 points if they don't rematch, but technically I can prove how he is wrong. As you can grow more if you don't rematch. (If you find the username who called everyone who doesn't rematch a coward tell me the user so I can get him in here.)
1. Not rematching and playing new opponents means you will play against the same minded player. You will see similar strategies and openings and nothing new. And if you're losing and winning them your ELO will be underrated as you usually don't learn anything against the same player.
2. Playing new people can open up a wide range of strategies, gambits, openings, and ways to defend more attacks. As not everyone has the same mindset, you will encounter someone who plays a very different opening compared to others, well it happens occasionally! This gives way more room to be better chess and actually perfectly have a rating that resembles opponents of similar ELO. If you just play rematches you will get the idea of people being almost exact to each other and actually lose ELO points when your actual skill is higher than your rating when you do play new people.
People who accept rematches might be losing their memory of other openings and strategies as one person can't pick up and remember all the things they learn.
I hope this makes you feel differently if you're the type to accept most rematches and see you're possibly losing ELO points.
Not trying to make any arguments but take this better than you do with rematches.
Playing the same person helps you predict them more easily which is useful
Lol he deleted forum I think