Well that question implies that there is some intrinsic reason not to build it as a web app. That may be the case for you if you prefer Kotlin or Swift or something, but it wouldn't be the case for me.
There is a quote that informs my thinking on this.
"The most amazing achievement of the computer software industry is the continuing cancellation of the steady and staggering gains made by the computer hardware industry" -Henry Petroski
Efficiency is very important to me. (And in the era of climate change, it should be important to everyone.) I consider web apps to be about the least efficient form of software yet discovered. We suddenly need two relatively beefy computers with multi-GHz multi-core processors and GB of RAM, one of which must be powered on 24/7, to do something that could have been done on the hardware of the mid-80s.
"The most amazing achievement of the computer software industry is the continuing cancellation of the steady and staggering gains made by the computer hardware industry" -Henry Petroski
Efficiency is very important to me. (And in the era of climate change, it should be important to everyone.) I consider web apps to be about the least efficient form of software yet discovered. We suddenly need two relatively beefy computers with multi-GHz multi-core processors and GB of RAM, one of which must be powered on 24/7, to do something that could have been done on the hardware of the mid-80s.