At this point, you should just expect any relays that are included as defaults/recommended with a client will be constantly hammered by new users.

Instead, use https://nostrgraph.net/relay_recommendation to find the relays with the best coverage based on who you follow, then check https://nostr.watch/relays/find to make sure the ones you add have a good uptime percentage.

This way, you'll have a good combination of connectivity to your nostr friends, but to relays that aren't overloaded.

Over time, clients will get smart about doing all this automatically for you.