My ISP is generally fast (75mbps fiber) but every 3-4 weeks there are 30min where my connection slow downs to 5mbps with 30% packet loss. The real problem that most people suffer is called bufferbloat (ping spikes when everyone else is using the connection).
I'm using a really simple QoS approach in my Mikrotik router, no real prioritization like CAKE or fq_codel in OpenWRT but it works pretty well at the cost of losing some brute speed (It's expected to get fq_codel in a future ROS 7.x release just like they did with DoH recently).
Before (ignore the 480mbps up bug, I measured the wan interface speed from winbox and it's just 76mbps)
After (shaper set to 68/70 mbps), notice how the ping mantains between 2-13ms compared to the above screenshot
PD: If anyone needs the Mikrotik config send me a DM
PD2: router model is Mikrotik hAP AC2 and I'm connected by 5ghz WiFi (DFS Channel)