Your WinMTR shows two routers (192.168.1.1 and 192.168.0.1). Not likely to be the cause here, but undesirable. There's at least 1 ping spike to the 192.168.0.1 router, which is odd if it's on the local network.
I've not seen you mention reinstalling TF2 (and starting completely stock first, no fancy configs) and reinstalling Windows, try those, in that order.
I see you've tried using your PC somewhere else and getting the same problem, but still, can you describe your network setup? Is it a true ethernet connection or something like a powerline adapter? Because those are almost as unreliable as wifi for gaming. What router(s) are you using? How are you connected to these routers exactly?
What kind of network adapter do you use in your PC?
Judging from your video, something happens causing you to receive less packets (see "in" packets/sec drop below 66 when it lags), but at the same time you appear to receive more data (see the "in" k/sec). This is counter-intuitive, but could make sense if these packets arrive out of order or are somehow corrupted / unusable.