> Being "modern" is not a sufficient explanation for why it is necessary.

It's considered commercially necessary because reading through logs is not as effective as using a Web tool like Google Analytics for the task of understanding what users are doing on a website.

If you want to make the argument that there's no difference between using e.g. Unix tools on a log file and using a tool like Google Analytics, that's your prerogative. But the industry as a whole disagrees.

> It is covered under GDPR but I think the general consensus is that server logs containing IP addresses do not require consent.

It depends on the legal basis. If you store these IPs to render service or combat fraud, you might get away from explicit consent. However, if you use and store these IP addresses for analytics, then it is a very different conversation.

GDPR is not just about what and how you collect and use data.