Especially as a solo founder (shameless plug: I run https://resend.io), I think this is the best way to both test your assumptions early, and to consistently ship improvements without spreading yourself too thin.
I've taken this approach as I set out to compete with companies with 100s of millions in funding and 100s of employees who had built out very feature rich and elaborate product platforms.
In my specific case, it went something like
1. build a shitty live chat plugin
2. make said shitty live chat plugin good
3. extend previously shitty live chat plugin with shitty automated messaging capabilities
4. make those shitty automated messaging capabilities good
5. and so on..
In between each step you should try and get people to use it, be shameless. You'll often be surprised that you can find users already at step 1, despite competitors already rocking well-established and mature solutions.
Doing this long enough (I have been going hard for 9 months), all of a sudden you'll find yourself with your own platform, built slowly by stacking one brick on top of another, and sticking to it.