Assuming you're looking for one lifelong partner, which isn't true of everybody, is it normal to find somebody "compatible" that quickly? Without apps, I think it's common for people to go for years between serious relationships. I don't know why the timeline needs to be so compressed.
For me as a fairly awkward and introverted person, who didn't naturally generate a high volume of new social contacts, one of the things I liked about online dating was that I could make choices more like an extroverted person. I didn't have to think, holy shit, I actually met somebody I get along with, and she seems to like me, I can't afford to let this go or I'll probably be completely alone again for years until I meet the next person. Instead, I could think, this is okay, but is this person a really good match for me? Does she bring out the best in me? Are we going to have disagreements about big life things?
In other words, I could meet somebody I liked, enjoy spending time with them, and still decide not to marry them. And do that over and over again until I met somebody I was confident was a really good fit for me. Like regular people do!
Even when finally I met my wife, it didn't immediately mean the end of dating other people. She had just started dating after many years of focusing on her career. In fact, after having a big heart-to-heart over wine with a close friend one evening about how she needed to start dating again, her friend helped her install Tinder, and I was the second person she matched with. Obviously, after many years out of the dating pool, she was leery of falling for the first halfway decent guy she met, so she wanted to take her time and see what was out there and figure out what she waned. To avoid going insane while she was meeting other guys, I kept meeting new women. We didn't become exclusive until six months after we met.
I think, if I had a single friend who was starting online dating, if they were using a paid app, I would recommend a 6-month plan or 12-month plan, as a reminder that they can afford to be patient and shouldn't rush into things.