Not necessarily, items still have to go through a review process.
You do have some cause for concearn however, depending on how Envato manages the issue and the participants in the market. Without a price floor, the market could easily become more competitive in the short term. Anyone who lowers their price while providing the same quality will inevitably attract more sales, but this also means other authors must lower their price, or, increase their quality to keep up with the market leaders which, if the quality route is taken, is highly beneficial to consumers.
What happens in paper is always different than what happens realistically however, you cannot expect everyone to do this; many authors would simply leave due to either a lack of incentive or being priced out of the market from maintaining marginal costs but lowering their marginal revenue compared to the larger authors who had already grown to a large enough scale to produce fast enough to overcome the lower price.
So, in the long run, Envato would end up lowing the diversity and volume of its author base, which in turn causes Envato to grow much more slowly than when it had a rapid influx of authors and also creates a oligopoly for the fewer large authors, which means at that point means those oligopoly authors have an incentive to provide lower quality items that are cheaper for production and Envato would have to accept and lower its item quality standards in order to keep competitive growth rates. Along with this, Envato also lowers its item diversity, which means it will be less likely to stand out in the market and therefore gains less benefit from the new items of the few authors.
Your instinct is right that ultimately an unregulated market with no price floor would likely do more harm than good, but only to the extent that it doesn’t harm Envato through authors charging so much that it is no longer competitive with other platforms.
It is also possible however that the market as a whole lacks the capacity for these top producers to use predatory undercutting against enough competing authors, and this will depend on Envato as well as the health of the overall economy that permits consumers to spend more money on assets. This is very analogous to the level of available nutrients in ecosystems that may permit the growth of only small organisms such as bacteria and amoebas or insects as opposed to the formerly lush ecosystems that support 50-ton dinosaurs.
The current state of Envato is in between both of those extremes, which is a good thing because it gives the market versatility. It lets successful items set a higher standard but still gives opportunity for growth to both new and old authors. A majority of sales do go to fewer authors, but not to the extent that anyone has a monopoly, so the future could take Envato either way. Lacking a price floor is one factor that would lead to predatory undercutting, but there are other factors beyond that which could compensate for maintaining the health of the market. Pond5 has a system where authors can set their own higher prices which has attracted a lot of very good producers, but not below a certain price floor. Their price floor in my opinion is too high, and I notice Pond5 authors almost always have less sales on Pond5 than on Envato, but despite that they’ve often reported higher growth than Envato and have a much larger reputation. There have been many times where I wanted to say Envato had a larger market share than pond5, but assuming there’s no fraud, when I looked at their numbers Pond5 always came out ahead.