Do you notice frame drops in things that don't have to use an active internet connection?
Laptops are notoriously hard to troubleshoot due to how many simple things could go wrong. If it's used a lot you may need to just clean it out dust and dirt wise. The thermal interface material could also potentially be breaking down. Failing components are also a potential source, but I tend to not look at that unless there are obvious signs.
How full is your SSD? Is it the only storage you're using?
SSDs don't do particularly well when they're full or close to full so this could be a potential problematic area.
How much DRAM does your system have?
Have you run something like HWMonitor/HWInfo to see if there are thermal spikes or if your CPU/GPU are operating slower than they should?