Back on sizing, Enduro MTB has an article where they ride race bikes from the pro. Here is some of that article:
"EWS professionals ride surprisingly short bikes – for good reason
The development of innovations always follows certain trends. Often the pendulum swings far in one direction only to level off somewhere in the middle. This seems to be the case with modern geometry. If you check out the race bikes on test, you'll probably be asking yourself how Richie Rude, who is 180 cm tall, can be so fast on a bike with a reach of only 460 mm. Jack Moir is 1.91 m tall and rides a size L Strive, which, due to the extremely tall cockpit, is guaranteed to have a reach under 460 mm. The mullet conversion on the GT Force Carbon that Martin Maes rides has also shrunk the bike down to less than 460 mm in length. The reason for this became clear during the course of our test. Not only did the shorter bikes record faster times, they also allowed our test riders to change direction more quickly and position themselves better before corners to carry their speed through them. On top of that, the agile handling of compact bikes is usually more fun. Anyone who thinks that these bikes aren't composed at high speeds can rest assured: handling stability is heavily determined by the suspension and all the bikes on test performed brilliantly in this regard.

Compact bikes are fast! For our 180 cm tall test riders, the medium Yeti performed better than the SB150 in L, which we reviewed previously. To prove our theory, we tested the Yeti and the COMMENCAL in both frame sizes. The smaller ones always came out on top.
Narrow handlebars are awesome!
Another trend that is swinging back is extra-wide handlebars. The professionals on the EWS circuit ride astoundingly narrow handlebars. The Renthal bar on the Yeti measures just 750 mm, the one on the Canyon is 765 mm wide and the Lapierre had a 755 mm model fitted. After taking a little while to accustom themselves to them, four of our five test riders found the narrow models better overall. They found them to offer more direct steering and increased freedom of movement, reducing tension on the bike with arms spread less wide. After the test, we ended up shortening the bars on our private bikes, starting at 770 mm. In any case, the fact is that 800 or 810 mm, as some manufacturers fit on their bikes these days, is too wide for most 180 cm tall riders."
I don't deny the benefits of longer bikes, it's just that there is an upper limit above which longer is not always better
"EWS professionals ride surprisingly short bikes – for good reason
The development of innovations always follows certain trends. Often the pendulum swings far in one direction only to level off somewhere in the middle. This seems to be the case with modern geometry. If you check out the race bikes on test, you'll probably be asking yourself how Richie Rude, who is 180 cm tall, can be so fast on a bike with a reach of only 460 mm. Jack Moir is 1.91 m tall and rides a size L Strive, which, due to the extremely tall cockpit, is guaranteed to have a reach under 460 mm. The mullet conversion on the GT Force Carbon that Martin Maes rides has also shrunk the bike down to less than 460 mm in length. The reason for this became clear during the course of our test. Not only did the shorter bikes record faster times, they also allowed our test riders to change direction more quickly and position themselves better before corners to carry their speed through them. On top of that, the agile handling of compact bikes is usually more fun. Anyone who thinks that these bikes aren't composed at high speeds can rest assured: handling stability is heavily determined by the suspension and all the bikes on test performed brilliantly in this regard.

Compact bikes are fast! For our 180 cm tall test riders, the medium Yeti performed better than the SB150 in L, which we reviewed previously. To prove our theory, we tested the Yeti and the COMMENCAL in both frame sizes. The smaller ones always came out on top.
Narrow handlebars are awesome!
Another trend that is swinging back is extra-wide handlebars. The professionals on the EWS circuit ride astoundingly narrow handlebars. The Renthal bar on the Yeti measures just 750 mm, the one on the Canyon is 765 mm wide and the Lapierre had a 755 mm model fitted. After taking a little while to accustom themselves to them, four of our five test riders found the narrow models better overall. They found them to offer more direct steering and increased freedom of movement, reducing tension on the bike with arms spread less wide. After the test, we ended up shortening the bars on our private bikes, starting at 770 mm. In any case, the fact is that 800 or 810 mm, as some manufacturers fit on their bikes these days, is too wide for most 180 cm tall riders."
I don't deny the benefits of longer bikes, it's just that there is an upper limit above which longer is not always better
