So I built something between 2020 and 2024, and while it was never actually profitable, it was getting pretty close... but then I hit a weird lag where my user usage exploded but profitability wasn't catching up AND various tools I was using in the low or free tiers suddenly required much bigger payments. Essentially my costs X5 but revenue didn't and I had to shut it down.

It was a good experience and I learnt a lot - but in hindsight I wish I had figured out a way from the start where revenue and profits always ran ahead of usage costs.

So yeah, you should totally build something, but think about revenue from the very start. Facebook/Amazon/Tesla, etc, weren't profitable for years/decades but their investors had such deep pockets - you and I don't have that luxury (I assume).