There literally are downsides ... like water spots! But first ...
Saying ceramic is better is like saying a phillips head screwdriver is better than a flat head; the key question is: for what??
The goal of ANY paint coating is:
(1.) To be a sacrificial layer for bird poo, road film, etc
(2.) Shed water & therefore dirt (hydrophobic),
(3.) To be shiny!
Every one of those goals can be accomplished with an LSP, wax, or ceramic and each have their trade-offs depending on your needs; none are "better".
The main downside to ceramic is you can't paint enhance after application; so, for example, let's say you get some gnarly water spots from rain or a sprinkler system and they dry in the sun. You're fecked.
If they're bad, they're there until you remove the ceramic. nothing you can do. lots of videos of very experienced detailers trying to remove water spots from ceramic. very very hard.
And this extends to any other paint blemishes that happen like swirls! To remove them you gotta remove the ceramic and reapply.
Why Ceramic?
For people who don't know how to wash their car properly (or don't want to or have the time), then getting ceramic is nice because it makes the process fast & easy.
Otherwise, I wouldn't recommend it for the reasons
@mountie said.
Why Not Ceramic?
If you're willing to hand wash your car every few weeks, and have the right tools, then there's no need for ceramic since you can (and should) simply coat the vehicle as a drying aide every time, thus there's no difference between ceramic and your freshly coated SUV.
When you use ceramic you lock in a single look for years!
Versus coating every wash: when you get tired of a coating, try a new one! If you get blemishes / swirls / water spots, then paint enhance them out.
SUMMARY
Ceramic is a great way to make routine washing easier and worry less about bird poop & bugs ... but it also prevents you from easily paint enhancing (polishing out swirls, marring, water spots, etc) and trying different looks & products.
Me?
I keep it simple and no ceramic:
(a.) If I've been in the rain, then a road film remover - I go cheap and use
Superior Products's Road Warrior available via special order at O'Reillys
(b.) Rinse off: I use a
Worx Hydroshot w/ de-ionized water from whole foods (0.39/gallon); portable, cheap, no hassle getting set up
(c.)
McKee's 37 N-914 rinseless wash into a bucket w/ de-i water and 8-10
Rag Company Chenille mitts - IME, these minimize micro-marring the best
(d.) I use the Garry Dean method: once a mitt comes out it never goes back in the clean water, 1 mitt side per "panel" (I can further explain if curious)
(e.) I use a
12" TRC Gauntlet sprayed with an LSP (usually
turtle wax seal & shine or
graphene flex wax) to protect & buff dry w a
TRC pfluffle btw, I use those products because they're cheap, easy, very effective, and can be used everywhere: windows, perspex, molding, etc - easy!
For wheels I do mostly the exact same, but first I clean the faces with a detail brush and the barrels with a
MM flat incredibrush
If the wheels have gone a long while then I'll use
P&S Brake Buster (or road warrior) first
Of course if there's caked on dirt then I spray it off first!
And if I get paint blemishes I can't stand then I'll paint enhance with an RO polisher and a 1-step polish, but generally I don't and leave that to the pros since I only do it every 6 months at the most.
I can do the truck in about 30 min if I'm working fast - only 1 bucket, and everything is portable. I've even do this on the road since it's so portable - if I'm on a road trip and get bugs, I spot spray them off and wipe off - TW seal-n-shine is very durable and holds up well for road trips, so it's what I put on before any longer highway drives!