Wouldn’t Gaea be better as a subscription?

No. We have run the numbers repeatedly, and a subscription would need to be priced higher to be viable. For example, Gaea Professional at $199 works out to roughly $8/month over two years. A viable subscription would need to be closer to $10/month or more, which becomes about $240 over two years. Over time, subscriptions cost more and stop working when you stop paying, while a perpetual license remains yours indefinitely.