If you want to have some fun understanding this better, call up (for example) Verizon and have them send you the data they have on you. It's surprisingly detailed, including timestamped logs of every DNS query (in addition to specific profiling data, like "how likely you are to buy a new phone" or "household income", etc).
https://www.verizon.com/support/download-and-view-vpd-file/
After doing this myself, I always (at a minimum) use a privacy centric DNS and never the ISP's default.
Comcast is the only non-56k ISP available in my area still in 2024. So I use them... but I also have to make sure to protect myself from their attacks. If I did what they're doing I'd go to prison. But some types of legal persons have more rights than human persons.
At least shadowsocks was well researched in the past, I'm not sure about v2ray.
The state, any state, often employs such tactics to make people believe they are protected, and therefore said people will act more openly. There are a myriad of such known cases, in fact the examples are endless.
So if one is in Russia... beware, for ways to get around blocking which work, may be ways secretly controlled by the Russian state. An example is a VPN service which is secretly run by the state, regardless of where it is incorporated or physically located.
Another example is blocking products which are effective, but letting products which are easily MITM by the state to "work", thereby providing the illusion of security and safety.
These tactics are thousands of years old, the employment of such methods is all that has changed. Make those which you distrust, use methods you control to organize. An example; the pub which is uses for meetings, is actually owned by state sympathizers, who claim otherwise.
To be honest, I think they are blocking anything that exchanges a lot of data with oversesas IPs, after hitting a certain threshold.