To some people he is. I dont see any logical argument to support this claim outside of things that cant be measured.
If you speak on things that can be proven and not with things that are "eye tests", then I cant see you making a strong case for Jon Jones. Most people will say he is the most talented fighter to ever grace the 8 sided cage. This I totally agree with. What he does to people at their own game rivals GSP at times.
What you can measure is his bodies build. He has the closes build to perfection that I have seen in MMA. Crazy long reach with both his legs and his arms. He can use leverage that makes him seem stronger then what he really is. Also hes strong as fuck.
But thats about it that will put him past the others who are in the GOAT debate.
He has a total of 8 title defenses and won an Interm Belt. Which is a record for LHW but it is not THE record for the UFC. Guys like Anderson Silva and Mighty Mouse both have 10 each. Jon Jones has won the belt twice with one being an interm belt. Which is not the record for LHW. Randy Couture won the LHW belt twice.
Some people say Jones is the GOAT because the resume of the people he beat is better then anything any other guy beat in the GOAT Debate while in a title fight. This I disagree with. Dont get me wrong, its impressive. But did he beat them in their primes or when they were about to fall off? We honestly dont know. Its not something you can for sure measure. What we can measure is how their careers went after they lost to Jones.
Lyoto Machida: 5-4 (2-1 at LHW/ 3-3 at MW)
Rashad Evans: 2-4 (2-3 at LHW/ 0-1 at MW)
Vitor Belfort: 4-4 (3-4 at MW/ 1-0 at LHW)
Chael Sonnen: 1-2
Alexander Gustafsson: 2-2
Glover Teixeira: 4-2
Daniel Cormier: 4-0
Ovince Saint Preux: 0-2
Thats a combined record of 33-28. Not that impressive. Now one can make the argument "but Brute that just proves that fighting Jon Jones will mess you up so much that your not the same after fighting him!". Again ill say "well thats not some thing you can measure. I look at the date and I see that it just means that Jones beat these guys when they were at the end of their peaks". But again thats not something I can for sure measure. So, take that data how you will.
When it comes down to it, Goat debates are always subjective. But I think the reasons why someone is the GOAT should not be. GOAT can mean mean one of 2 things most of the time. Those things are (A.) He/she is either the best to ever do it in their field of sport and on their best day cant be beat by anyone (MJ,Ray Robinson, Jerry Rice) or B. Had the biggest influence on their sport ever (Ali, also MJ).
I think Jones is the closer to fitting (A.) more then (B.) for sure. And while I do think he is the best LHW to ever do it. I think guys like Anderson Silva-Mighty Mouse-Fedor-GSP are closer to being the unbeatable fighter on their best night then Jones is. But again, thats subjective. What those guys do have over Jones is that they have longer title reigns and number of defenses. So again, when it comes to thing you can for sure measure. Jones does not stake up.