Artist Guweiz, in their lovely book, talks at one point about the need for validation, and how trying to satisfy that need can be deceptive. It's not that validation is bad; we all want validation — yes, even people like me who have a fanbase of six and are okay with that.
I don't think we want validation just to know that we're doing the right thing, but also to know we're not doing the wrong things. In the sense of knowing we're not hopelessly off the rails and out in trackless space somewhere. We want someone else with their feet still on the ground to call out to us and say "Yes! I can still see you from down here!"
These feelings arise most strongly in people who don't have a lot of mutual support. The greatest hunger for validation arises in people who are new to this, or who have labored more or less in a feedback vacuum (and are correspondingly suffocating). They conclude, not all that incorrectly, that people who have fanbases in the thousands or higher are doing something right, and since they don't have such a fanbase, they're doing something wrong! If they could only know what it was!
Everyone needs some level of validation, just as everyone needs some level of constructive criticism. The two can travel hand-in-hand; the best critics know how to tell you what you're doing well along with what you need to work on. It's just often difficult to get them in the same place, since many people who are willing to give feedback are not always trained to provide both validation and constructive advice.
If you can find yourself one or two people who can give you such meticulous feedback, hold on to them for dear life. Failing that, find people who can give you, separately if need be, constructive feedback and constructive validation. We all know what the former is like, but the latter is trickier. It's not just flattery, but statements like "This character reminds me of people I once knew," or "This passage is the one part of the book I keep coming back to." Specific things that can be unpacked are always best. They give us an idea of in exactly what sense our feet are still touching the ground.