It really does.

I work at a big accountancy firm as a software developer so IT is quite security minded, and while our ThinkPad T470p notebooks aren't top of the line, they should be at least faster than my Dell Latitude E6520 of 2012 which both have i7 CPU.

We run Symantec Endpoint Protection and this antimalware software is quite intrusive. I had an exception for a week to run with Symantec completely disabled, and never had a better working laptop. Still quite slow, but a good bit faster than usual.

Since the Spectre microcode updates performance has only been getting worse.