It was a bug in macOS. I think it’s fixed.
If there is significant swapping there is no fix for that, it is still swapping and still utilising the SSD? However way you look at its more use of the SSD. There is no free lunch with swapping. Its not to say all SSDs will fail. It really depends on how much swapping takes place. If you test an 8Gb machine with 256gb that's swapping against a 16Gb that isn't, then you will not only see the difference in performance, but every swap is a step in the finite lifetime, especially of a 256Gb SSD.
So whilst a marketing man boasts to the effect that 8Gb unified Ram is as good as 16Gb on Wintel, it totally avoids the ramifications if the device has to swap with the SSD, which does reduce longevity of an SSD, such factors as write amplification factors play their part.
Of course trim helps, but if there is significant swapping, especially if the SSD is low, then its life will be shortened.
The problem for customers is that it probably won't occur when the device is under warranty, but if it was considered that selling an 8Gb machine with 256Gb was bound to mean significant swapping, and I would suggest selling a machine as pro with that line up would put Apple in for a potential class action, especially when they've openly suggested words to the effect that 8Gb is the equivalent to 16Gb on Wintel, without consideration of the potential problems that can create, and especially on any equipment with 'pro' in its name, as I wonder then if it would be considered fit for purpose.
Far better for Apple to recognise that if their aspirations to move into Gaming are to be realised, they will have to increase the base unified memory and likely the SSD too.
So better to react in advance of a problem then carry decent PR with it, than to continue with 8Gb 256Gb base configurations.
Even if it means increasing the price a few dollars, because I haven't seen any caveat warning from Apple about SSD failures as a result of buying a base configuration and doing so if being assured by any marketing person, it was fit for purpose.