BA F was superb until 2004, then they got caught in a perfect storm. A convergence of a need to cut costs, labour troubles, aging fleet, improving competition and mis-management in the responses to these problems. Leading to year after year of decline in the service aspects of the airline (I believe the technical operations are still superb, 3-engined 744 flights not withstanding). Overall BA remains firmly in the top 10 airlines in the world; so still well above average, and the same applies to the FIRST service. But it is not what it once was, and it clearly will never again be what it once was. How ironic as BA pioneered the concept (first with suites, etc.) and really inspired the competition to revamp their F products to be at a much higher level. Now it seems BA simply cannot keep up, or rather is relying on T5 to be the basis for a service relaunch.
To be fair to the BA FAs, the F staffing level was based on F not being full most of the time (and in fact it was rare to be half full until a few years ago) and this allowed more time per pax for service. It also perhaps conspired to create inefficient procedures and a lack of investment in outfitting the galleys properly, etc (I like to look at airline galleys and it is amazing how much diversity there is, with some such as CX and LH having completely different galleys -- for the better). Now that BA is often selling J with F seating on some routes and corporate contracts, F is always full, and they really need an extra FA or more efficient procedures. If they want the service level restored, that is. Unfortunately their competition does.