Sometimes. unneeded aftermarket software like anti-virus, so-called "cleaning" apps, and over-hyped client-side VPNs (those not issued by and employer for access to work systems) can drag down performance instead of "helping you protect."
If you are not sure what may be on your Mac Pro, there is a safe, secire way to show us. If you want a data-driven evaluation in this setting where we can neither see nor touch your computer, please post an EtreCheck report. We can quickly and within the limitations of these forums help you determine what issues are at play without our playing a protracted game of "20 Questions" with you that could go on for days.
EtreCheck Pro is available here:
https://etrecheck.com/index
The free version will do nicely for this purpose, although the app is worthy of our financial support.
We can see hard data about drive performance, software interferences, and RAM usage. Etrecheck is the development of a long-serving and trusted ASC contributor. It is a reporting app, not a "fix-it” app, expressly for displaying information in these forums to help us help you remotely. It will not reveal any personal or secure information.
Please see this excellent user tip on how to post long text reports like EtreCheck's into a forum response:
https://discussions.apple.com/docs/DOC-250000211
Please post the entire report unexpurgated. What seems insignificant to a new Etrecheck user can speak volumes to those of us who have reviewed thousands of those reports.