Yes it is very ill advised as people often do important tasks on the PC including banking.
To put this in perspective. There were 1,360 Vulnerabilities reported in 2024. Not single one will be patched post end-of-life.
There are vulnerabilities that were waiting for end-of-life to be exploited.
If I use my malware a month before EOL and it’s caught then I have to start from scratching. If I do it after EOL then I can reap the benefits forever.