... but can router with SQM algorithms improve this situation considering limitations set by my ISP?
YES! Before I moved, I had 7mbps/768kbps DSL service, and an IQrouter was a simple, clear solution. It was never "fast", but I could sustain two zoom calls (me and my wife) quite nicely.
IQrouter is easy to set up, and will almost certainly solve the problem. (If it doesn't, you can always return it to Amazon, but you won't want to...)
Update: To answer your question: No, low upstream speeds don't cause bufferbloat. It's your router (DSL modem) that is blissfully unaware of how much data it has queued to send over a low-speed link. IQrouter uses the SQM algorithm to take control of queueing/buffering so there's "just enough" data to keep the pipe full without adding delay. I'm proud of my Best Bufferbloat Analogy that explains how SQM works...