very much so; but you can:

1) save your balance in relays you don't expect to delete

2) save to a few relays

keep in mind that as long as a single relay has your balance you have access -- so if your nostr client / wallet notices you are down 1 out of 3 relays with access to your wallet balance it can warn you or publish to another relay

for you to lose your money you would need to get rugged by your various relay at the same time