There is a longterm upwards trend in BA fares since the pandemic (probably not surprising), interrupted by the occasional sale:


The figures are the average lowest fares across all destinations (essentially what you see on ba.com when you look at the lowest fare finder page), so they are not what most people pay, rather what people would pay in the best case scenario. You can ignore the up and down spikes for early 2021, there was an issue with the data feed.

The full data is at https://speedbird.online/farearchive.php.