DFS is more important in US than pretty much anywhere in the world due to strict FCC ruling around U-NII-2A band. Take a look at a great table of channels summary on wiki: https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(802.11a/h/j/n/ac/ax) it shows three big things:
DFS isn't exactly a new shiny thing which was just introduced and people need to adapt. It has been with us for over a decade:
In 2007, the FCC (United States) began requiring that devices operating in the bands of 5.250–5.350 GHz and 5.470–5.725 GHz must employ dynamic frequency selection (DFS) and transmit power control (TPC) capabilities.
It has been years since I used any ISP-provided hardware and I personally opt for solutions from Ruckus, MikroTik, or Cisco. However, as this isn't representative I simply did a spectral scan in my house. There are 67 networks on the 5Ghz band. Around half of them operate within the DFS range. We don't have Verizon FIOS here but looking at SSIDs XFinity/Comcast devices indeed avoid DFS channels while AT&T devices prefer them.
Pretty much every manufacturer supports DFS in their AP gear, especially in higher models. Listing companies doesn't make sense here really as I can reply "any besides those who cheaped-out on FCC certification" as any 5Ghz 802.11ac-supporting chip on the market supports DFS (and there pretty much four player here: Broadcom, Atheros, Intel, and Realtek). One of the OEMs making consumer and prosumer devices will be Netgear which even have a convenient table, listing pretty much every device they make in the last decade: https://kb.netgear.com/000060372/Which-NETGEAR-devices-support-Dynamic-Frequency-Selection
Samsung S21 does support DFS as a client and I see them connect to our corporate network on the daily basis, as some of the APs must run on DFS channels due to congestion. Every single Apple device I've seen since the draft-ac days also works with DFS channels. I have two ATVs (4K models) in my own house and I can assure you they do support connecting to a network running DFS channels, as this is the only 5Ghz network I run. To my knowledge there's no extra certification needed to support DFS & TPC channels from the client perspective, you just need to be certified to operate in that frequency range. There are only extra steps to support DFS as an AP, and here's where Roku cheaped-out.
DFS is more geared for business than residential customers by a longshot. I have the knowledge to setup my own DFS devices at home, but to me spending a lot money on business grade equipment is something I don't do in my house.
This desires to emerge as a factor, I stay in an condominium complex, and there are a long way too many 5ghz networks round to choose the tool click counter, in addition to my net connection coming in, is operating wireless on a Ubiquity Prism 5, the use of uni three for a clean connection.
DFS is more geared for business than residential customers by a longshot.
What makes you say that DFS is geared towards business use? DFS was actually meant more for consumer use rather than business. If all 5Ghz networks within the weather radar range were operated by professionals DFS wouldn't be needed. We know exactly that with the indoor powers used and proper placement of APs there's no significant outdoor leakage. In any serious deployment you use surveying tools before and after to fine-tune powers (and you tune them down). As the experience shown, DFS was needed for in-home deployments because everybody was setting the channel to Auto-All with the maximum power (because more=better, right?).
There's plenty of hardware (and really nothing exotic here, literately a $50 router/AP) which will let you go around all the regulations - you can just disable TPC and DFS on it and run it on any channel you want, even way outside of the prescribed channels. However, such devices aren't and shouldn't be used by regular consumers. What is intended to be used by regular customers are routers from BestBuy which use DFS. Roku is the only device in my house, which contains somewhere around 100 devices, which supports 5Ghz but doesn't support DFS as a CLIENT.
DFS-protected channels aren't a luxury - there're a necessity in densely populated areas (i.e. condominium complexes), ESPECIALLY in the US where every wall is paper-thin.
Business' have more money to spend and the need for extra bandwidth that can be utilized with DFS that the average household does not need. I used to live in a neighborhood with over 1700 townhomes and there was no Wifi interference on the 5ghz network experienced by me and everyone else in my house.
Hard to believe this is still an issue. I have a 160 MHz channel width which is impossible without DFS.
So my choices are:
1. Move my entire SSID to 80 MHz on a non-DFS channel and lose wifi bandwidth and add congestion with nearby neighbors
2. Buy an Apple TV