Some perspective from someone who has worked in hospitality: Some brands have fought back in creative ways.
An essential part of being listed on Booking or Expedia is to agree to never advertise lower prices anywhere else, including your own website. That means you can share a $100/night rate on your own brand's site (with no commission) and you can't tell Booking or Expedia to show rates over $100. Thus, users have no advantage in going to a hotel's own site, which only shows their own brand's hotels. Expedia/Booking on the other hand show you all the hotels in the area and you can be confident in price-shopping (the one exception is loyalty points, but if you're a price-conscious, non brand-loyal customer, that won't matter to you). Worse, competing hotels can get better visibility by sharing even lower rates and promotions on these aggregators, and it becomes a race to the bottom, really hurting hotels long-term just for visibility.
Choice Hotels had an interesting response a couple years ago: they show a "member-only rate" on their website. In the above scenario, technically, their public rate is $100 so Booking would take around $20 leaving $80 for the hotel. But Choice might also show $93 as an option on their website only for members (which is free to join, only takes an email/password). This way, technically their members-only rate isn't being advertised for just anyone so they don't run afoul of their Booking/Expedia agreements while only losing $7 as opposed to $20.
Last I checked, Booking and Expedia didn't like this and they docked Choice Hotel visibility in their searches because even if it didn't run afoul of the agreement, they still have discretion over their search ranking.
These aggregators don't need to disappear. They just need to lose some of their leverage over hotels. If all hotel brands banded together to offer their own "members-only" rate and customers became aware of what's happening, I'm sure it would really help out hotels long term.