Maybe better wording would be a risk of time - not a waste of time. Very good work can be done building nostr right now it's just that it might take luck and that dev might be focused on projects with more guaranteed success
Discussion
I might be projecting but that stance feels like a cope.
worst case scenario there is as much risk in developing on nostr as there is on going to the gym.
rewards depend on your goals and whether or not you are doing the work
Going to a gym that only has one machine though.
Maybe a safe machine where you're unlikely to injure yourself - but the likelihood of wasting time without results is higher than a full gym.
Buy more machines, build more machines