Like Adnam's, Harvey's and many others, GK's yeast it isn't a single pure strain of yeast, nor is likely to be from your local brewery after 46 years without washing, and most probably not in your 20th pitch of whatever. Whilst GK may have had all the isolates, it's improbable they knew the exact ratios at the time they lost it and so struggled to get back to where they were.
- From Greene Kings website.
It is this complexity of multi-strain pitches that differentiates them from single strain dry yeasts, not the process of drying. Neither is more live than the other.
Take Nottingham for example, it is the primary strain isolated from a brewery, so unlikely to replicate wet yeast from that brewery. Its like comparing apples to a fruit cocktail. However, once this is understood, one could use a mix of dry yeasts with total control over the characteristics of the beer, with zero risk of drift, under or over pitching, contamination or having "call it a day with this one".
https://www.murphyandson.co.uk/wp-content/uploads/2018/09/Yeast-Nottingham-Ale-Yeast.pdf