Every golden weapon is 3000 Competitive Points.
You currently get 15 CP per win, 5 per tie, 0 per defeat.
You also get CP at the end of every season depending on which rank per role you resides.
There are 31 heroes, so you need 93000 CP in total.
In order to get all the golden weapons you need to be GM on every role for 4 years, for each season.
Otherwise, you need to win 6200 competitive matches. It’s approximately 1500 - 2000 hours of constant competitive matches… excluding queue times. (checking my statistics)
From my point of view, it’s an immense amount of time. I would end up living under a bridge if I wasted all that time. Not kidding.
My suggestion is to AT LEAST increase the rewards in this way:
30 CP per win, 20 per tie, 15 per defeat. (additionally, you can increase to 45 CP per win for tanks, and 35 CP per win for supports)
It still requires 150 matches (with 50% of win-rate kindly offered by MMR-senpai) to get a single golden weapon.
Honestly, it’s still very high even like this, but it’s better than nothing. Most of the people don’t even keep playing comp after the placement matches. They have no motivation (since there’s not even decay).