Yes, but keep in mind you are not wide broad audience, you are you. The guy took his money and for roughly a price of 2 month subs or 5-6 skill injectors upgraded his witcher 3 to have all the paid DLCs. Boom, he now has an immense entertainment value for a long, long time to come. It will take him a year or more to play through all that.
You have to think in broader terms, how to pull people into skilling up and staying for T4s as you gave in your example, instead of doing stuff like this, all in fraction of time and all costs, not just monetary but personal as well (investing yourself into your toon). So think in terms of broad total general entertainment value vs total general entertainment value, not specific stuff, because in essence, this is what is needed, to provide people with general entertaining value vs other things available to them at same cost, time and personal investment.
You can argue all the sandboxes or whatever boxes you want, but thats the bottom line of it. To stay afloat, the game needs those people to stay here, instead of elsewhere and pay money on top of that. Also, vast majority of people coming in only focus on the fact that this is a space MMORPG, not sandbox or whatever else. They find out all that stuff once they are here, not before.