DRM makes sense - if you find it reasonable that content creators get paid for their work - so an open web standard is better that multiple conflicting proprietary standards.
Having it as a standard means that all browsers will have to include it if they want to conform. Binary blobs (especially closed source) are the antithesis of a free and open web. I suspect firefox will keep it optional but, like all closed source programming, it's impossible to be sure that it's not doing anything if disabled. Remember Flash? How malware prone it was? How buggy it could be? The amount of CPU/RAM it took up? I certainly do and I don't want anything like that forced upon me.
I do not see DRM having much of an impact on piracy. If anything I'd expect to see an increase as 4K takes off - the requirements for netflix 4K in particular are particularly onerous:
Netflix said:
Microsoft Edge up to 4K...Streaming in 4K requires an HDCP 2.2 compliant connection to a 4K capable display, Intel's 7th generation Core CPU, and the latest Windows updates. Check with the manufacturer of your system to verify specifications.
Source:
https://help.netflix.com/en/node/23742
Then recall that they can change that any time they like and everyone will need to get new hardware to watch in 4k. I can totally see people pirating 4K shows and whilst I don't bother myself I certainly empathise with those who do. DRM lasts until it's cracked too unlike traditional copyright law
I want content creators to get paid as much as the next person but as a consumer I also feel that I should have the right to make personal backups, store it in any manner I see fit, convert it into whichever format I like, consume it on as many devices as I like simultaneously regardless of network status and software/hardware combination. And to have all of them in perpetuity.
That certainly sounds rather
Stallmanite but consider a physical CD you may have and count how many of the above you can actually do with it.