Godspeed! I don't think Ariane 6 will go down in history as a successful rocket, mostly on account of the shift in economics forced on the rest of the industry by SpaceX. But I do get excited for debut launches -- some very clever people worked very hard on this. :)
If it reenables European sovereign and independent access to space it's a success. Fingers crossed that it's also as reliably as A5. Commercially I agree.