I actually looked at going to Scilly this year, but with the demise of flybe on the Newcastle-Exeter route, and a 50% increase, since my previous trip there in 2018, in the price of a flight & ferry combo I just couldn't justify the expense. For a bit of fun, I looked at a Newcastle-Toronto return via LHR on the dates I was looking at for Scilly, and once I'd included the necessity of at least one night in Penzance, there was only a few quid difference in price.
A shame; as davidjohnson has said, Scilly is a very special place, but unfortunately due to the pricing of travel there it literally is a 'one-off' holiday in the nature of what a trip to Canada was for me in 2003. Having said that, it is still worth going there for that 'one-off' trip. It sticks in the throat, though, to pay over £150 for a return trip of the same distance as Loganair in Orkney do for £30-odd.