Your battery is apparently failing, and that can diminish performance. The expected replacement cycle count is 1,000, and this Mac is at 1,666: Determine battery cycle count for Mac laptops - Apple Support
If the battery is swelling, that can initially cause problems with the trackpad, and then problems increase in severity.
VPNs can effect performance, as well.
Not enough memory for the load. The Intel i3 processor is also not speedy. Virtual machines, Office, Google apps, all need lots of memory, and lots of processing.
System load is heavy, too. Activity Monitor app can show some of what is active.
No backups? That can be bad. The only way to mark data as valuable is with backups.