That is true, but IPV6 is basically used for Wide Area Networks such as the Internet. I think you will find that the routers designed for home use assign all the Local Area Network devices IP addresses based on IPV4.
I have a Netgear Nighthawk RAX75 WiFi 6 router. It is my understanding that it can handle over 200 Iot devices because they have low traffic loads. If you are using more demanding clients like computers, tablets and cell phones, video streamers, and voice assistants etc. then you are likely to run out of bandwidth far sooner.
As initially configured, most home routers run using a subnet of 255.255.255.0 which means that local devices can be assigned addresses from 1 to 255 using IPV4. Typically the router is assigned as device 1 such as 192.168.1.1 on my router. Different routers might use other addresses. Older routers might not have a fast enough processer to handle 256 clients, even though you might be able to assign that many IP addresses.
