Why would the point of v6 be to entirely replace v4? That's such an impossible to accomplish goal even if v6 was the most perfect protocol to ever exist and even if you didn't believe that by that point v4 was embedded in so much hardware as to be physically impossible to replace without incredible amounts of hardware recycling problems, including some dangerous deep sea diving and missions to space. Even in your own home you indicate you likely have hardware that you aren't in a hurry to replace.

The point of IPv6 was always to build an internet that could address the next several billion devices. IPv4 addressed way more devices than its developers ever intended and did an arguably above-and-beyond job at addressing the first billion or so. (We can argue for hours though on how hacks like NAT44 have broken some of the original spirit of IPv4, of course, in the course of prolonging its useful device addressing lifespan.) IPv6 is succeeding in that. There are emerging world devices getting addressed that could never afford a cramped IPv4 address. There are nearly as many mobile devices running IPv6-only or IPv6-first as servers in the first couple of decades of IPv4.

Will all of the "first billion" devices move to the new protocol? On the one hand, probably not. On the other hand, does it matter? The dream of the internet was always about bridging a bunch of networks that had no right talking to each other and that many people thought it impossible that they would ever speak common protocols. There's only one internet because no matter how complicated it gets, people are still cobbling together incredible ways for different stacks to talk to each. This is how the internet was built, this is how the internet will always exist. This was true in the era when internet tools were built out of putty around unix-to-unix copy somehow speaking to VAX servers across an Appletalk bridge to a token ring ethernet adapter to a proprietary IBM Mainframe protocol. It is still the case with IPv4 and IPv6 acting as side-by-side "friends" working together for the common good of the internet.

The internet doesn't really care if you only want to run "one stack" instead of two if you are fine that an increasing amount of your traffic is going through the equivalents of an Appletalk bridge, who may start charging for it at some point (or are volunteers running it for fun and might get bored). (I think in this analogy the biggest one of those Appletalk bridges is Cloudflare? Even I can't tell if I'm joking or not. It does explain some things about CF's business model.) It will take decades for it to get to that, though.

Anecdotally, my home ISP grants me an IPv6 allotment and I've noticed quite a bit of traffic using it. It's kind of fascinating because my current Wifi router indeed has some sort of memory pressure issue with some combo of IPv4 BGP routes and NAT44 firewall states and just entirely falls apart routing IPv4 at some point when it has been running for long enough. My previous employer's IPv4-only VPN seemed to especially stress it for whatever reasons, during WFH life, and I'd have to restart the router somewhat regularly for it to start routing IPv4 correctly again. IPv6 traffic just worked even when the router was dying on IPv4 traffic. If I wasn't on my work laptop or trying to use a site like HN or GitHub, I could go sometimes hours to days before realizing IPv4 addressing was broken again. My "prosumer" perspective is IPv6 is the reliable stack I use most often (gaming, lots of daily browsing, key apps I rely on, even many of my consumer devices just quietly falling back to 464XLAT and "Teredo" tunnels and still reaching IPv4 stuff despite my local router falling apart) and IPv4 the increasingly weird and flaky stack. I only know I can point a finger at IPv4 because I'm just enough of a nerd to do small bits of debugging when it happens out of curiosity, but it is an interesting pattern, anecdotally.