Sampras and Borg shouldn't be on the same tier as the Big 3. Sampras never made a Roland Garros final. While he had more clay court specialists in his day, none of them were Nadal who single-handedly prevented any other RG winner 14 times in the Big 3 era. Borg's hole in his resume is never winning the U.S. Open. Also, McEnroe should not be on the same level as Connors and Lendl. McEnroe was every bit as talented as them, if not more so, but he shouldn't get extra credit for that any more than Kyrgios should because he's not sufficiently motivated. Connors was crazy good at his peak and would very likely have won the Grand Slam in 1974 had he not been banned from the French Open. He would probably have around 15 slam titles if he had been able to play RG at the peak of his powers and if he wanted to play the AO. He only ever played the AO twice and won it once and was runner-up the other time.
Also, I was alive during the Borg, Connors, McEnroe era and watched them play.
Big 3 would also be having similar tallies as Sampras/Borg if they were in those eras, so why can't we place Sampras in the tier of Big 3 ? When we compare across eras then we adjust the parameters and extrapolate to compare, that is how comparisons are always done taking into account inflation.
Slams won by the 30th birthday
Federer - 16
Nadal - 14
Sampras - 13
Djokovic - 12
Borg - 11
You cannot compare 1 Million $ in 2025 to 1 Million $ in 1975 without adjusting for the era. The 11-14 kinda figures if extrapolated in the modern era with greater longevity and other benefits they all come to 20+
10 Disadvantages that Sampras faced compared to Big 3
01. He was from USA, travelling was a big issue, if he was from Spain/Switzerland then he would have no problems travelling to tournaments and playing even after marriage.
02. Thalassemia - affected his stamina, big 3 never had this problem
03. No weak era mugs in next generation - Sampras never had this because in his 30s his next gens were Hewitt/Federer/Safin/Roddick who were all better than 90s gen.
04. Slowing down of courts and the rise of poly strings which made it harder to adapt in 30s, today Big 3 don't have any such problems, their strengths in their 20s remained in their 30s too over the field.
05. Sampras did not have homogenization in his time, there was supreme diversity which also affected his chances to win the french. In his time the clay courters would easily claim that they could kick his ass but today no clay courter can kick anybody's ass, neither can grass courters, today it is an era when everybody is a hard courter and everyone is same on all surfaces.
06. In his era players were more injury prone than they are now, so careers were much shorter. Today you have the GREAT AGE SHIFT.
07. Today there are players travelling in private jets with their army of physios,, trainers, this was not there back then. These things actually are benefits for the top players, so this too played a big role in the prolonged careers in the 30s.
08. 16 seed system which made it harder in the era of Sampras because it could produced surprised defeats, in today's era the big 3 were unaffected till the QF because they know they can pad up their numbers and play into form by the QF unlike those days.
09. Presence of Social Media in the 2000s and 2010s makes the Big 3 to be bigger stars and thus bringing in more money for them, so more ways to get better when you get more money, no ? Your enhanced Stardom is a gift of social media, even an introvert like Nadal signs big money deal with Saudi Arabia.
10. Last but not the least, Tennis was not about only Slams. There were more surfaces and more tournaments in the era of Sampras. They even skipped Aus open in some years and their focus was on davis cup, tour finals and plenty of things which don't have a lot of relevance today.
So Big 3 having a Slams Race (chase would be the better word because they were actually chasing Federer rather than racing against each other) in the end and going 20+ should not be the licence to put them in a higher tier than Sampras or even Borg.
Since you said you have watched Borg-Connors, that means you are probably 20 years older than me, so you should be well aware of these 10 points I listed, you should not hype the big 3....