If anything, trimming *ought* to result in improved performance once it has completed.

What kind of SSD is that, and how much does it trim each time? My 512 GB Samsung PM981 NVMe takes less than two minutes to trim about 30 GB each week

/: 86.2 GiB (92560949248 bytes) trimmed on /dev/mapper/monotone-root real0m8.208s (1TB Intel 660P) Both your numbers sound terrible.