What's your question here? The premise of the OP is that they created a fast issue tracker.
People complain about Jira being slow (me being one of them.) No one has claimed that all issue trackers are slow. ClickUp, Hive, Linear, are all snappy.
The comment I replied to said that trackers are slow because they are full of stuff, and when you try a new tracker it feels fast because of lack of stuff.
I think you might be misinterpreting him. When I read that, "full of stuff" meant old tickets, process that you had to go to, etc. Slow =/= app performance but general cruft.
I don't think he literally meant that the app's performance was slowed down by the volume of tickets. I don't think Jira's performance gets much worse even with 10,000s of tickets in it.
The baseline performance of the web app is just baseline bad though.
"New issue trackers feel faster for the same reason switching browsers tends to feel faster—you're getting rid of all of the crap you piled up in the old one. Don't migrate your backlog, start with only a couple engineers in a new issue tracker, and suddenly, wow!, this new tool is so much better!"
People complain about Jira being slow (me being one of them.) No one has claimed that all issue trackers are slow. ClickUp, Hive, Linear, are all snappy.