When COVID started, British Airways introduced a temporary reduction in the number of Tier Points you needed to upgrade your tier status and renewed tier memberships so that it was easier to keep their elite status, while there was little or no travel at all. This was similar to what other airlines did (SAS, Air France, American, etc.)
With the increased demand for travel in 2022, British Airways just announced that they will be re-introducing the standard Tier Point thresholds at the end of this year.
British Airways Tier Point Thresholds will be updated on 1 January 2023
You can continue to benefit from the current 25% reduction on tier thresholds until 31 December 2022. From 1 January 2023, you must meet the full Tier Point thresholds to upgrade to Bronze, Silver, or Gold.
You can find more information about these changes, including the full tier thresholds and answers to frequently asked questions here.