This happens everywhere. Privacy considerations aside, asking a user to download an app is just like placing a brand name on his/her main page, so that they're not just constantly exposed to it, but will be tempted to use the app when in need, real or ad-induced, of something to purchase.
For Internet company, user is what generates value. So it make since for those companies to grab their user as tight as possible especially when the competitors are doing the same.
On the same note, if a user just don't want to login or use the app, then the user is no value or even a negative value for the company. For that, a company can intentionally annoy (the actual word used is Convince) those users until they give in.
With all that been said, what I wanted to point out is, sometime, parasite can be successful. This is why we have many types of parasites in the real world. Automatically assuming "'parasites' will just die" is not going to help if the end goal is to kill all the parasites.
"we can't possibly have apps for anything that spark our interest. that just won't work!"
Exactly. That was how the internet worked before the web (and still does today): pop/smtp, ftp, nntp, gopher, etc. had each one its own client because they were different protocols doing different things. But today, when phones have a working web browser that does what 99% of apps can do and more, it's against any logic forcing people to install an app for every brand, sometimes for every product. That would be ok for mail, news, file transfer, IoT, music, video, etc. because they're way different things, but installing 5 apps to read 5 newspapers or buying 5 products from 5 different vendors is like throwing into the toilet all innovation brought since the web was invented.
I can guess only three reasons for this: sticking a brand name into the user screen, bypassing browsers adblockers, and getting a foot into the door for nefarious purposes since most apps require insanely dangerous privileges which one day could be exploited.
