I've read enough answers on this platform to know that Alex and Rahul are huge fans of learning Android, both because it's a well-established area of tech (bigger than web) and because you can see how well your apps do. They always mention learning Android, but from my limited understanding, React Native gets you iOS and web as well, and is similar to regular web-dev (could totally be off here).
Isn't it more bang-for-your-buck to learn React Native and perhaps a better use of time?
It really depends on what your goals are: Both approaches have a lot of value.
...Alex and Rahul are huge fans of learning Android, both because it's a well-established area of tech (bigger than web)...
Web is much bigger than mobile as it's more established and was the first front-end platform. Mobile is just hotter due to being more modern and the paradigm shift towards it, but I'm confident there are more web developer positions than mobile ones when you account for all companies, not just trendy ones where many are mobile-first startups.
All this being said, there's far more to an app than just the code - You need to maintain each product and slog through their release cycle as well. Let's ignore web and just consider the fact that React Native also gives you iOS "for free" on top of Android. It's very much not free as now you have to:
In 90% of cases, I recommend the following path: Do native development in the platform you use personally.
You're an iPhone person? Download Xcode, learn Swift, and publish iOS apps.
You're an Android person? Download Android Studio, learn Kotlin, and publish Android apps.
Passion is such an important factor in side project success as the #1 cause of death for side projects is not finishing them or iterating on them enough due to lack of energy and motivation. When you build apps that you yourself can use, play around with, and share, your excitement level is naturally 10x higher.
The reason I was able to get into Android development back in college 10 years ago (and eventually turn it into a massively successful career) is because I had so much fun and fulfillment just deploying my janky Android apps to my Samsung S3 and being able to see them work (or break hilariously). My roommates were also Android users, so I could share the apps with them as well - It was good times.
And of course, 80% of software engineers want to break into Big Tech someday and native development is 100x better for that. Even though Meta literally invented React Native, 90%+ of its mobile engineers do native development.
If you're interested in learning Android, here's a great thread about it with links to learning resources: "How can I get really good at Android?"
Lastly, here's the masterclasses I gave around building effective side projects: