The "Trending" sorting of the World menu is favouring older worlds over new worlds that drive innovation and have a more fickle playercount due to it.
Currently the Trending/Hot algorithm does not take into account when your world has been uploaded. This is a problem, because it means newer worlds have no way of ever being given a chance. People tend to move where people are, so it matters little what kind of world you have as long as it has a lot of players in it. Therefore as a new ambitious creator your only chance is to make use of your initial push of curious explores to grow a playerbase.
This is not possible with the current algorithm, because it is hard for a new world to get among the top worlds on Trending. Which is what most people will see on the new Trending page, as it opens by default when you first open the World menu. And since you only see "trending" worlds as you scroll down on the new UI this makes it even worse.
Please take into account how most people will use your UI, I do like the other features you have added to improve discoverability, however the algorithm that determines how things are ranked in Trending will overall make discoverability even worse.
The Solution to this would be to give newer worlds more weight on its ability to rank up on the Trending page. Aka your heat level.
It should be structured in a way where worlds that got out of labs a while ago (lets say 1 year old ones) are virtually unable to rank high on the Trending page. On the other hand new worlds with less players (but still having people in it ofc) should be given a boost. That way a new innovation/concept can be given a chance for a short time while it is still fresh to see if it is fit for the test of time.
Think of this time based weight as an Exponential Regression Curve whose weight goes to 0 after 1 year.
Please also note that resetting the Heat Level every 2 weeks is not an adequate measure, since the level will bump itself up within literal hours if you got people already in it when it happens.
It can not be that you have to employ some jaded marketing strategies to get your world seen. I am telling you this from experience as Mr. HomeBox. I benefit from the current algorithm btw and made a documentary on how exactly 2 years ago, that may have found its way to you a while back.
As it stands now you have 18 out of the top 20 worlds on Trending be over a year old. By adjusting the algorithm with a time component you will not only keep the game fresh, but also encourage creators to give it their all, as they too now have the ability to be seen on the illustrious front page of VRChat.