thosr who received delegation grow their witness vote rapiidly through voting on their own posts and curation
Ah, so your point is that because they get more Steem Power this way, their witness votes grow bigger too and thus they have a larger vote to give their own witness?
If this is your concern then it's simply not a very big problem. 1. Delegation receivers are not allowed to self-vote their posts, as it is considered an illegitimate use of delegation according to the guidelines. I know some have done this in the past, but it's a minority (we've never had more than 1% self-vote in a 31 day period, and usually only vote our own post less than once per month, which is close to 0). 2. These projects are usually powering down to fund their activities. While this may be another problem, it does mean that their witness votes are really small (almost never above 40k SP).
So the whole argument that they will grow over time thanks to the delegation and that it will impact witnesses is simply not holding up. Even if they somehow did power up everything you're still only looking at maybe 100k SP per year. Which is very, very little in terms of impacting which witnesses are in the top 20, or even top 50.
Lastly, even if I were to grant you all of the concerns you've laid out, I still don't think it is a big problem relative to the problem of other stakeholders not updating their witness votes. I don't even want to count how many witnesses we still have in the top 50 that have not made a single post or other forms of contributions to Steem in more than a year. Or who are even working full time on competing projects... This is far more problematic, as at least the delegation receivers have to be active on Steem, and rely on its security, sustainability and growth in order for their projects to be more valuable.
I don't know if you care much for Steem at this point, but perhaps you should shuffle around your own votes first since you're still supporting witnesses that have abandoned Steem completely and are missing blocks, have not updated their feed in months/years.