As for the follies, had they just been used as monitors they would have been ok. Once the inherent flaw in Fishers speed = armour was recognised they should all have been completed as the carriers the navy was crying out for post Jutland.
I agree that completing Courageous and Glorious with flying off decks like Furious would have been a great improvement on Campania and the converted railway ferries.
However, in the short and long term their existence was the worst thing that happened to the Royal Navy. Their conversions to proper flush deck aircraft carriers in the 1920s cost about £2 million each, when a new ships of the same displacement would have cost about £4 million, carried more aircraft and had better protection. If they hadn't existed the RN would have had 4 aircraft carriers in the middle 1920s (Argus, Eagle, Hermes and Vindictive) and without any ships that were suitable for conversion I think its very likely that the OTL 1924 Plan for a force of 7 aircraft carriers consisting of 4 new ships of 17,000 tons and the 3 Follies by 1938 would have been replaced by a plan for five 27,000 ton aircraft carriers or six 22,500 ton aircraft carriers by the same date. I also think that its very likely that the Cabinet would override the objections of the RAF and Treasury and allow at least 4 of them to be laid down 1924-34. That is 3 in place of the OTL Folly conversions and the fourth in place of the OTL Ark Royal. I am prepared to sacrifice 3 County class cruisers (cost about £2 million each) if the Treasury won't cough up enough money to make up the difference for the £12 million to build 3 new ships and the £6 million that it cost to convert the 3 Follies.
In the shorter term my cruiser plan for World War One is to build 12 D and 8 E class cruisers instead of the 12 D, 3 E and 5 Effingham class cruisers ordered, but only 8 D, 2 E and the 5 Effinghams actually completed. Due to some jiggery pokery the D class are built with six 6" in 3 twin turrets and the E class eight 6" in four twin turrets, which AFAIK was feasible technically, but wasn't done IOTL because single open mounts were thought to be better.
This means no Effingham class cruisers were available for conversion to aircraft carriers and the E class built in their place were too small. Therefore instead of converting Vindictive and building the OTL Hermes to satisfy the requirement for 2 North Sea aircraft carriers a pair of enlarged Hermes class were built. The ships were larger because instead of the 40,000 shp machinery they were fitted with E class cruiser machinery producing 80,000 shp because a higher maximum speed was required. This meant a larger hull was required, but it also meant a larger hangar and longer flight deck.
Also in my TL Eagle is completed as a battleship in World War One and after they war she is sold to Chile along with the Canada. Therefore the requirement for 2 ocean aircraft carriers is met by the OTL Argus and converting the Italian ocean liner Gulio Cesare, which was proposed several times during World War One IOTL.
IOTL Argus and Vindictive were completed before the end of World War One, but Eagle and Hermes weren't completed until well into the 1920s. ITTL I hope to have Argus, Gulio Cesare and the Super Hermes built instead of Vindictive to be completed by the end of World War One, with the Super Hermes built in place of the OTL Hermes completed several years earlier than the real one.
In my TL there were enough resources to build the ships because a cut in merchant ships construction was possible due to an earlier introduction of trade convoys. However, it could also have been done by not building Hood and starting her cancelled sisters.