I was thinking "dating app", not "catalogue". The problem is that is becoming a major part of dating.
A significant chunk of dating app use is done by non-serious people trying to get laid, where appearance is going to factor in differently.
For those who are serious about finding a long term relationship there are more serious apps, where I imagine people are given more careful consideration.
But yes if you're not the ideal type it's reasonable to expect it to be a little harder under any scenario.
My impression of dating apps (never used one as I've been married since before the internet) is that they are pretty much only useful for getting laid. Match has bought up almost every other dating app out there and remade them in it's mold. Someone just looking to get laid will keep coming back for more, someone looking for a relationship isn't a very good customer because success leaves them
not coming back for more.
Well the primary purpose of dating apps isn't technically a relationship, it's connecting with others.
Why you want to connect isn't something the app can really control. But as you mention, those looking for quick hookups are going to be there in higher proportion by definition. Because the app excludes everyone who's already found someone or is no longer looking.
I know at least one married couple who met via online dating. It can work if you're serious about it.