Depends. If it's a hobby, learn both to be more valuable.
If it's for a business? How much money do you have to throw away? Does the app pay for itself, or is it a cost centre? (99.9998% of the time, it's a cost centre.)
You really asked the most boring part of that question. Most of the answers below suggest that the app is defending its territory, etc. Malarkey.
Just like you're not winning the lottery, you're not writing a standalone app that can pay for itself.
Why? Hundreds of thousands of apps exist on each platform right now.
For your app to stand out enough to be successful it needs synergy with something. A web site, a service, a IRL business.../something/.
Tha says to me: do the cheapest possible thing. If you have React devs, use that. If you don't, find the alternative cheapest possible way. Flutter? Maybe. Nocode (like Glideapp, https://www.nocode.tech/category/app-builders)? Maybe.
Pick the fastest/cheapest way to get an app out to validate the concept. Once validated, then you'll have enough information to know what pain points you have, and what solutions you /really/ need.
I feel you're missing the point of Apple's "guidelines", such as they are.
Apple's rules are what Apple says they are on a given Tuesday.
They can (and do) allow apps that flagrantly violate the guidelines, as well as refuse apps seemingly based on the direction of the prevailing wind, and unless you have an internal contact at Apple to protest, you're stuffed.
Developers can do whatever they like with Xcode installed, but good luck distributing anything like this reliably.
You can't master Software Engineering without mastering interfacing with the rest of the organisation.
I don't care how intellectually pure your implementation is or how fast you deliver things. If it can't easily connect to, use and get used by the rest of the business, it's a folly.
A master of software engineering delivers what the business needs in the minimum time possible.
Some businesses care about maintenance. Some don't.
Some care about UI/UX, others with a trapped audience don't.
Some care about efficiency and optimisation, others don't.
You can't be a "master" until you have a sense of what your business is interested in. Not what it CLAIMS to be interested in, but really cares about.
It's been different in every company I've ever worked for.
In my experience the UK is slightly less focused on credentials than the backwards boneheads in the US.
That's the good news.
The bad news is that tech interviews in the UK tend toward the same faux-IQ test mentality.
When are recruiters going to realise that just because you can reduce a person to a HackerRank score, that doesn't inform a good hiring decision?
I've often said the only way to see how someone is going to work out in an office is to hire them and let them work for a month on probation. After a month, if they've demonstrated an ability to talk, to collaborate, and to learn, then keep 'em. If not, cut 'em loose.
everything else in tech hiring is B.S. I have yet to see an alternative that can't be gamed, that takes in the holistic person.
And none of my jobs have really brought out the best in me. In jobs I've done well, I drove that myself. In jobs I didn't, it usually came down to bad communication (in both directions). Nothing to do with the recruitment at all.
For heaven's sake, please let this mean that Google finally gives a shit about wearable devices!?!
I know wearOS devices have been struggling. I hate the thought that I have to buy a watch from China to get decent battery life (a Huawei band 2) which means that my data goes through some sketchy companies in China.
I already have given everything to Google. Why would I want to do that for Huawei, Samsung, and whoever else is making hardware?
I want to control when my devices talk back to a server and what they say, so I started using net guard and monitor the URLs my data is going to.
I want to see the data stream so I can get even more detailed in my blocking efforts.
I could really see how this would help corporate types. We have lots of reports, etc, that would be so much more informative in-the-hand rather than in-powerpoint.
However, that would require allowing a company to be self-hosting. We don't use Slack, for example, we use RocketChat, as no information has to go off-campus...it's all stored locally.
It's effectively an online desktop publishing system aimed at making it easy for HR teams to deliver TRS (Total Reward Statements) in 10% of the time, at 10% of the cost, and with fewer errors.
It took a couple years to write, so I wouldn't say it was an easy investment, but it was fun to write. These days it ticks over and I don't spend much time on it at all.
I bet they're nice.