What is your evidence that investing time into mobile would increase the likelihood of finding a job? Would you pivot to something else when/if the mobile market also gets saturated?
Since you have experience with frontend, mobile apps seem like the logical choice here.
But web development is huge. Are you saying you can't find jobs that _pay well_? Maybe you can consider specializing further into web development for more lucrative types of business, go into consulting and charge per day/week instead of hourly, etc.
You haven't elaborated on what you have tried already so it's hard to say if you've exhausted your options in your current area.
Collecting specialities is important, but never think of yourself as a "front end engineer" or a "mobile developer", you're a software engineer that has happened to specialize in two previous fields.
My last three jobs I've done big data, SRE, network servers/socket programming, distributed systems, and more.
Some companies will hire you for your speciality, and others will hire you because you're good at learning a speciality, and they might have a new one they want to point you at.
Mobile is tricky, people mostly transfer into it from another specialisation and you’re expected to have a pretty deep knowledge of whichever platform you pick. If you go the Flutter/React Native route you’ll need experience on both and language experience in multiple languages.
Competition is less and saturation is less than web but there’s also far fewer jobs.
I’d second what others have said and hone your backend experience further and expand into devops.
If you do go the mobile route. Android development has more demand. Apple has a lot of developers, android not so much.
Yes, just go wherever wind blows. At least you’ll improve the skill of switching career paths.
i'd say if you want to go mobile go with react native and expo.
The overall state of the software job market is quite poor so don't expect things to be much better if you switch to mobile. In fact you should expect it to be more difficult to find a job in mobile development because your experience is less relevant.