Woah 3 meters is really far for a 60 inch. I have a 60 inch at about 1-1.4 meters and it's great. Perfect for two people on a couch with some nice bookshelf speakers heavily toe'd in. It's not great for entertaining, but for watching things it's honestly better than some theaters.

It's all about how much it fills up your field of vision and how closely your retina's resolution matches the display's resolution. I don't want to have to turn my head at all to see things, and still be able to use my peripheral vision to have good awareness of the entire scene, and not see individual pixels if I can help it. But, still have it fill as much of my vision as possible while within those constraints.

Been wanting to upgrade to a 70-80 inch screen, too, at the same distance.

Another big variable is height placement of the tv in relation to one's head height and angle while comfortably sitting where you'll sit. Sit, close your eyes, sit comfortably, play with tilting your head forwards and back until you find a comfortable and sustainable pitch angle, with your eyes still closed look directly out from your skull, open your eyes, and that location is where the middle of your tv should be (it's usually about 10-20degrees down from directly ahead, but is different for everybody and your seating position and body). So if your tv is 3meters away, your optimum tv height might be on the literal floor. (And also speaker woofer and cabinet size for the volume of the room (bigger speakers for bigger rooms), and placement, depending on viewership location and count, go for an equilateral triangle between your seating position and the two speakers and default to having the tweeters at ear height with no obstructions and pointing at your ears for the most accurate imaging and least amount of comb filtering, and keep the woofers and tweeters vertically aligned to minimize time variance, which is good for stereo image, and try not to have you or speakers too close to walls or especially corners).