@anil Great question!
@TomV pretty much nailed it with his response, but I had a few points I wanted to add. All of my tubeless experience has been with fat tire bikes, which are highly functional with a tubeless set up as you can drop your air pressure really low and get the most flotation possible out of your tire. As such, I can't speak with direct experience to road/gravel riding while tubeless. However, I have some friends who ride road/gravel with tubeless and they really enjoy it.
Advantages of tubeless:
- Helps prevent small puncture flats and eliminates pinch flats. This can be particularly helpful if you are riding gravel where you may have issues with thorns.
- Allows you to run with lower pressure, which can make your ride more comfortable and actually reduce rolling resistance and make you faster. This can be helpful if you ride gravel or varied terrain where adjusting your pressure can be a big advantage.
If you're not the kind of rider who is going change your tire pressure depending on the ride and you tend to ride with your tires at max pressure, going tubeless probably will not give you much of an advantage. If you simply want an extra layer of protection from puncture flats then a slime tube is likely your best bet there. Installation and regular maintenance are definitely a factor going tubeless so if you want something that is simple and won't require a lot of work then a slime tube will work better there as well.
However, if you don't mind putting in the extra work to get the best feel for your ride and you ride varied terrain where tire pressure matters, then going tubeless might be a great option for you.
Hopefully this helps, thanks!