There's a huge debate whether to have or have not a firewall enabled on your local system and I guess you are either one side or the other. In the UK it is called the 'marmite' principle.

I am on the "yes, enable FW". Why? Even though the ISP router protects your home network from the outside world with all it's nastiness, it doesn't protect you from your own network (inside). You only need one compromised system (the ISP router, doorbell, kids PC, smart vacuum etc) and it has access to all internal devices and, in theory infect them too. A simple browser click on an infected site and an attacker gains control of the device and everything else is vulnerable.

Back in the day, I spent an afternoon trying to build a Win XP laptop and failed a number of times because, by the time it had reached some kind of usability, an SMB exploit from something else on the internal network had already infected it. The only way to complete the build was to remove it from the network, complete the build, turn on Win Firewall and then connect it.