it should not be that hard or difficult to activate a game licence on GOG of the same title
Sure it is, which is why they don't do it, other than in extremely few & rare circumstances that are so rare that they might as well not even exist.
The bottom line is that GOG doesn't have enough money to compete with Steam and/or Epic Games Store, period. No amount of "great ideas" is going to change that fact, so "great ideas" on their own can't change anything if the wads of endless money is not there to back them up.
Short of GOG receiving a colossally massive influx of money and/or being bought out by a company that has such amounts of money, then GOG will never be able to compete with the big players.