Power Query becoming extremely slow while comparing multiple daily Trial Balance files

So I am an intern at a finance organization. They have a daily Trial Balance, and recently I wanted to compare numbers from daily TBs side by side. So I made a Power Query setup by putting all the TB files into a folder and fetching them date-wise to filter relevant data and group it. Then I used the generated output in a Pivot Table to get a ledger-wise and date-wise comparison of values.

I want to do the same for many items in the TB and also expand the date range. Currently, I am doing it for 15 days, but later I may want to do it for a month or even a quarter.

The problem is that it gets too slow and heavy. Every TB file is around 10 MB, and the query takes more than a reasonable amount of time to refresh.

Especially in front of seniors, when they suggest alternate ways or ask for changes, it takes forever to edit and refresh the query.

Has anyone handled similar large-scale Power Query setups for daily Trial Balances?