Took my car to get a lot of suspension work done a month or so ago.

Part of the work to be done was replacing the anti roll bar bushes, as the car is really loud and creaky when making tight turns.

Indie told me they were unable to replace the bushes as they couldn't remove the bar due to the bolts being seized into the nut inside the chassis. They tried to remove, but the bolts started to round off rather than turn. They explained that if they sheared, they would need to be drilled out and the chassis needing to be retapped.

The front lower and rear upper suspension arms were replaced, so the car drives better than what it did, but it's still really loud when making tight turns etc

Should I take this to another mechanic and see if they can do anything with it, or do I have to just learn to deal with it?

Definitely take it somewhere else.

Drilling and tapping a sheared bolt out is something any competent mechanic should be able to do.

Except those roll bar bush clamp bolts are very difficult to get to. Hard enough to get a spanner to them, impossible to get a drill to them. Pete
2008 L320 TDV8
2022 Hilux Rugged-X

Two of the bolts you can see the end of the thread from under the car, so on a ramp may not be to bad to drill out but the third one is captive inside a welded cross member so impossible to see captive nut part and drill, however as the thread on that one is not totally exposed to the element might be one that will come out intact, If you remove the front propshaft it may give more access to the passenger side bolt heads to get a better fitting six sided socket and see if they will undo, might also be worth soaking them in penetrating oil for a few day's and take it to someone who has the right special tools to fit the bolts.

Cheers
Col

Having had both front and rear ARB's replaced on my MY10 3.0ltr I can relate my experience.
The front ARB bolts are awkward to get to and there is a special LR tool used (there have been threads on here).
The rear bolts on mine were very rusty (it came from Scoltlandshire with their permasalt roads) and the indi I used to use had a go and just changed the drop links, which didn't cure the clonk. I took the car elsewhere and they reported that the bolts were on the way to being rounded (at least the previous guy knew when to stop) and they had a real job getting them out. Apparently gallons of penetrating oil and a conductive heating tool were the answer. What they said was if the bolts shear/rounded and they cant get them out, the body has to be lifted to gain access to drill them out.
I hope this may help explain why some garages are reluctant to tackle the job Also why I didn't fancy having a go myself on the drive.
I guess if the bolts are in good condition, and the garage has the right kit it's not such a big deal.

Thanks, this makes sense. Is it safe to leave the it the way it is then or what should my next steps be?

If it was my car, I couldn't live with it and would try and find a good indi who will be able to properly assess if they can do the job. Armed with the information gained from here, you can ask a few pointed questions so you are happy they know what they're doing. It may be that you will have to have the body lifted if the worst happens, and it would be worth getting a quote in case so you know how wallet draining it could be.
I don't know what will happen to the bushes long term if not replaced but your clonk is not going to get better. Will they totally fail and fall out? Will the ARB itself be damaged? Is it an MOT fail?
If you do have them done, it may be worth considering polybush replacements rather than the rubber LR items as they will last longer.

Try another Indy