I have climbed, highest mountains

Mountains in minecraft are not realistic, the build limit is around 150 blocks I think? Which is not even considered a mountain, it's a hill! I know that adding mountains like everest would cause so much lag, and changing the mechanics may cause some things to break. But you know about these things, Im just gonna recommend my ideas and a way these can be added, maybe. • Highest mountains, mountains can now go up to 600 blocks!Up to 300 blocks you can find new species of plants up there, like oregano and some rare flowers! Above 300 blocks nothing grows like in real life that above a certain height, nothing grows. •Fjords, volcanoes, and other beautiful landscapes. •Palm trees, more temples, more marine life and deep trenches • Bigger caves and maybe an underground world very deep in the earth, like in Jules Verne books. • Make ravines, worth going again, please do it for the old players! I know most of these can never be done, but some maybe can. Highest mountains can be optional and the player would be warned if his device can run it or not. Volcanoes seem a bit too much but could be a great source for lava, obsidian and magma blocks. Palm trees can be added and marine life can get a second update. Anyway these are my ideas, I hope they are taken into consideration (btw it's a video game, dont say my ideas are not like real life or sth)