This isn't always the case and there are definitely some things that are made more difficult working away from the office. First is the lack of people, normally I'd be sharing an office with another person and there is the rest of the team in adjacent offices ready to have a chat or discussion. Second is the type of work being done, if you're doing something that can just be done with minimal input from other people then being sat with few distractions can be very efficient but the opposite is true, if you require input from a number of people then distance will hamper your efforts. Finally is the timing, there's a natural rhythm to office life from when people arrive to when they leave an it's very easy to stick within this rhythm. Outside it you need to ensure that you're working at the right times and more importantly finishing at the right time so you don't overwork yourself.
Fortunately the weather has gone back to the British norm (cold and wet) so it's ok to go driving back into work. Hopefully we'll have learnt a bit from the enforced remote working so when it next happens we aren't impacted quite so badly. How the rest of the country copes, well we'll just have to wait and see.