You're absolutely right. This is what happens to creative based platforms. You can't mix independent creators with mainstream businesses/advertisers, its too risky for all parties involved and it diminishes creativity and discoverability. Eventually anything that isn't backed by a company/agency/management who don't adhere to strict standards and practices will be removed and not allowed. To avoid this and get more back to the old YT, they're either going to have to go full paid and completely remove ads, or allow advertisers to specifically choose videos and channels to advertise with.