I think a big part of the equation is how long someone has been here and who they are connected to within community. Also what level of rewards the person considers to be worth the time investment. Regardless of how much we enjoy socializing, most people have to be a bit practical about how they invest their time and factor in both enjoyment of the community and financial returns.
You are fortunate in that you've been on this platform long enough that people you started forming relationships with when they were also new have all grown with you to have considerable stake. You also have a lot of followers. This allows you to post multiple times per day and know you'll get a decent payout on each one. So in your situation, the value is definitely coming far more from community interaction than you would ever get from delegating or vote selling.
I'm fortunate that while I wasn't nearly so early as that, I was able to buy a considerable amount of SP. For a few months I also was a part of a community that provided large once-daily upvotes. This combination gave me the ability to be generous with my upvotes, building my community connections more. I still delegated about 25% of my SP because I wanted to be a part of some communities that required the delegation, but with dolphin stake, it wasn't a big deal.
But then the community I was in provided upvotes with no delegation lost its major delegation. But I was still held to just one post per day by my participation in the other communities. Suddenly I was not making enough for the time investment for me to consider the endeavor worthwhile. At least not as a regular thing. I then wound up changing my delegations to more like 65% of my SP, which in combination with the decreased price of steem, has made my upvote pretty tiny again. It's back to being like a minnow.
Other people are less fortunate than either of us. They joined after RCs were introduced, so came into an environment where they could do less AND where there is simply less activity on the platform overall. And I'm not just talking about missing spam. There is less genuine engagement also. So it is much harder for them to earn on their posts than it was for either of us. Even if they buy lots of SP, the chance that it will come back to them through others finding their content is very low. If they want any guaranteed returns at all, they'll need to delegate in some sort of way.
Tricky business.
Indeed it is and this is why people have to better consider their actions here. As you said, I and you are fortunate in many ways which allows the luxury of passive action but, it has also come at a cost. For you it has been a financial one earned through sweat in the real world and allowed you to take different paths here, me it was a sweat to earn on here through consistent activity. I think that those who have come in after RCs and can't power up from external sources need to think through their expectations and wills at this point although there are possibilities to come.
Those with small stakes have to consider how best to use their stake. There are many options here but it is difficult to do what is best for the individual if they don't understand all of the possibilities, implications and ramifications of their behavior and the external influences that affect them. I am not judging people, I want people to find options that best satisfy their needs and many are unknowingly using their stake in a way that doesn't necessarily get them to where they want to go.
There are new options coming that will change this but that is going to come through new interfaces and SMTs. For many, the better use of their resources at this point might be to support and earn future SMT stake or hold @steemmonsters cards. Every position has risk and reward involved though.