You're right, we can do better.
We've been keeping our smole relay fast and healthy is by periodically pruning events. Paid users like yourself still get longer duration. Occasionally when we see the usage spike, we dial up the pruning. Rinse repeat over the last year and now events expire within weeks rather than months like when we initially started. It's time for us to grow with nostr a bit, so we just paid to lease an affordable dedicated server in Kansas. This will increase the duration that we can keep posts, like more than 10x (last time we had a dedicated server we didn't prune at all). We backup our event store regularly, so when we migrate a lot of old events will get restored on this particular relay.
Our costs increase as well, so we're working on improving our web of trust model and eventually setting up subscriptions.