I'm not sure if it's rare, maybe just not talking much, I'm not sure either. Maybe I can share some possible reasons on why mobile is pretty much a beast to tame, or a thing some prefer to avoid, just my opinion though.
As for technicalities, one example is, at the moment Godot 4 with "mobile" render method (Vulkan mobile, cough) has issue with black screen for some GPUs (you can look at it here). Luckily it's still possible to run gl_compatibility, although with the least graphics feature available. That issue alone is enough to tell how hard it is to develop for Android ..., erm, I mean mobile devices.
I believe that the old or cheap PC nowadays is capable to run mostly on what Forward+ can offer. Simply put, with PC, you're more focused on what you can deliver artistically than what you can't. Even if mobile can get more fancy features, battery, heat, and shared memory are still your biggest enemies, and I don't even get to frame synchronization/consistency and display with various refresh rates nowadays.
The other thing is likely monetization. Certain PC market lets you publish a game with upfront sales, or at best, you add DLCs. I believe, this means you can focus completely on the game itself without being bothered to balance your game over ads and in-app purchases, unless of course you decide to sell "premium" games to mobile.
I think some indie devs simply refuse IAP monetization model due to its addictive vicious cycle it can provide (a.k.a compulsion loop), some just believe it's really that hard to incorporate them in, especially dealing with the after-sales (top up failures, failed ads that won't close, oh my god!).
You can also check the difficulty in terms of distribution by looking on how to export Godot games for Android/iOS, compare to Windows. For example for Android, there are these things called APK, OBB, and AAB. I've published APKs before, but not AAB. AAB is the latest, and likely Google may ditch APK distribution in the future, or I think it's already done, since 2021? I don't really check the news. I'm not even sure how that works yet.
After that you got the tedious store requirement and policy reviews, and it's A LOT to deal with; icons, screenshot sizes and policy, privacy policy, permissions, internationalization, ratings, device selections, is it landscape/portrait, does it require internet or not, is it for ipad/iphone/both, review, and moreee. Don't forget to deal with the manifest file first too! Just saying that this is a challenge too to keep up with the OS and what the store wants.
As for the market, as you said, mobile market is pretty much over-saturated that it is hard to break. You can tell that on how the two companies proudly brag on how many apps are in their play/app stores more than the quality of the apps. Honestly I don't know how to make it in that battlefield either. but what I'm sure mobile market is vast and vary. It's not as if we got to capture all audiences. For example, there are some outliers where the players don't like it when they downloaded a 45 MB game just find out they have to download another 2 - 4 GB of data in-game. Not to mention some parts of the world don't always have unlimited data. It might be the reason why games with low package size that is casual cute idle game, clicker game, and stupidly funny viral game is also and still popular, I'm not sure. I think it's challenging market that's worth to try. I mean, we're indies, right? We take risks... right!? Okay...
Lastly, obviously preference. Some just prefer PC/console. Period.
I made two mobile games before in 2012 and 2016 I think, both failed miserably (not counting mobile web games, cause I assume this is play/app store thing). The first one was for iOS, and I couldn't continue to pay its yearly developer program so it got shut down. The last one was in Android. It was weirdly casual my mom couldn't even understand what to do with the game. so I wasn't proud about it either I pulled it faster than ever rather than polishing it (only a month!). Please allow my excuse that I was just testing Unity on Android!
I don't give up on mobile market yet, though. I just like mobile platform, I guess. The joy of being able to show what I'm doing just by bringing my cheap phone or play it however, whenever, wherever I want always makes me feel good regardless of my dim success in mobile market. 🙂