Hello @NicolasD, I have used Jira service desk in the past and I have to say it's quite good, also my company still has several instances of Jira running.
However I think that Jira is quite expensive we got an offer for 3 admin operators for about 40k a year which is completely berserk.
Either way Jira is a good, highly customisable and if you take the time you can make it extremely user friendly.
Hopefully you will find something that suits you.
Best of luck