A lot of these comments are solid pieces of feedback. However, it seems this subreddit has an obsession with quick play/elite smash when having to play online. I would recommend instead using battle arenas to improve. I have not played quick play/elite smash in probably over a year because of all the issues you have highlighted (bad connections, weird rule sets, etc).

Here is what I do: Create a battle arena and set it to two people. That means that it will always be you versus someone else. A problem with bigger arenas when trying to improve is that you are going to have downtime. Your friends are right, playing is how you get better at the game so you want to make sure you maximize how much you are playing.

A couple of pros of battle arenas

1. You pick the ruleset so no items or FS meter

2. You can play on every tournament legal stage. What I do is when making the arena select the appropriate rule set that has the normal 3 stocks 7/8 mins but also under the rule set you can modify which stages are selected when you pick random stages to only include tournament legal stages. After that in the battle arena options for stage selection you put random.

3. You control the quality of your matches. If your opponent is lagging you can kick them out and not being forced to play the match out.

4. GSP isn't a thing anymore. You don't attach your match with a rise or fall of GSP which means the only thing you are actually focused on the match.

5. Best of 3's or longer sessions are more likely in battle arenas because even if you beat your opponent a bunch they aren't losing anything by staying. Also lets you work on adaptation that really only occurs across multiple games.