When I was using qBittorrent in a container in a Rasperry Pi 4, it was definitely the raw power that’s was throttling my downloads. You may wanna check CPU usage, specially if going through a VPN.

Also try limiting the maximum number of connections and slots for download and upload. You want to connect to less people but still use the same bandwidth, which is basically transmitting more data to those people.

How are you “among the firsts to get a torrent”? In private trackers, people use special software to be the very first, and on top of that seed-boxes with 10, 40 or even 100 symmetrical Gbps. Check “autobrr” to get started. It is not uncommon that you for example reupload a torrent from other tracker to get some sweet ratio and somebody cross-seeds your torrent and starts uploading before you.

Generally people aren't maxing out their download bandwidths, so if you have peers and are below your upload limit, the bottleneck is either your computer (e.g. disk, CPU), your network (e.g. WiFi, Internet), or the peering between your ISP and theirs (e.g. Deutsche Telekom).

Other people have kind of touched on this already, but clients prioritize connections based on stability and speed so things like seedboxes often get utilized more than your average home client to saturate a downloading connection.

I also noticed that my max upload speed is much less (e.g. 2MB/s) than what I get with speedtest (e.g. 7MB/s)

Again, other people have touched on some bottlenecks that can cause this (y'all are good lol), but clients also have a bit of connection overhead that will ultimately affect your maximum upload speed to peers at a varying degree. Here's some details, if it helps:

Overhead- Additional data used and required for communication and coordination between sender and receiver that is not part of the payload data actually being transferred.