First, let's get one thing out of the way.... it WASN'T three years. It was FIVE.
Here is the 49ers record leading up to 2019, The previous 6 years.
Year Wins Losses Divisional Place Notes
2013: 12 4 2nd Lost in SB
2014 8 8 3rd
2015 5 11 4th
2016 2 14 4th
2017 6 10 4th
2018 4 12 3rd
4 straight losing seasons. All with double digit losses. That's how they had so many top-10 and top-5 draft picks. People here are complaining we went 7-9 and pick 13th. Who is ready for lots more losing on this level? I don't think you'll find many hands raised.
Also, the 49ers lucked into getting Jimmy Garrappolo for just a 2nd round pick. That's a gift wrap for a franchise level quarterback.
So, San Francisco was terrible for far longer than this thread recognizes. It came with much more pain that Colts fan can withstand. And they got a gift in finding their high level QB.
Winning in the NFL is flat-out incredibly hard. It's not as easy as saying... look what the 49ers did! Much harder.