What are the pros n cons of applying for deferred entry vs applying next year

I've just found out I'll have to take a gap year due some personal reasons

That being said, I have now to decide whether to apply this year for deferred entry (2021) or to apply next year.

All I know so far is that if I apply for deferred entry I have to give reasons and what I'm planning to do throughout this year in my personal statement (kind of a con)

Which course? For most courses you really don't need to go into any detail. If you think that you do just say that you plan to work for a year.

Biology and Biological Sciences. Yeah, I've checked uni pages and they all ask to state reasons and how I plan to spend the year. I kinda do have a plan which sounds good for unis

Thing is I dont really understand how applying now for deferred entry in 2021 would be different from applying next year. Like would they process it differently? no clue

Ok - outside of a very few universities biological sciences type courses are somewhat undersubscribed so it wont make any difference at all. Loads of people apply for deferred entry to save money, have a break, think about what they want to do, travel etc. The universities won't be very bothered about what you say your reasons are.

You raise a good point about the difference between applying now as opposed to next year. The benefit is that you might have a place ready and waiting once you have completed your A levels and not need to think about it for a year. If any were to want to interview you its pretty easy to go and visit. If you slightly miss the A level grades you'll have a faster response about whether they will still take you.

The benefit of applying next year is that you will know what your grades are so can target universities more carefully, and will have had an extra year to think about where you want to go and exactly what you want to study.

On balance it probably doesn't make a lot of difference at all in most circumstances.