Earlier quoted context omitted.
I think reaching 1400 elo after a year of decent study after learning the rules is not too unreasonable. To reach 1400 in a year you would need to be either talented or hard-working. Climbing the elo ladder does get much harder though, as you mentioned. To reach 2000 in two years you would need to be both hard-working and talented. To reach 2850 in a lifetime you have to be hard-working, talented, and a particular No…
In which format? I highly doubt that someone could do that in bullet unless they played full time. Bullet players are already on average a higher percentile of chess players so the elo is skewed
Generally speaking, players playing bullet are more interested in having fun and less interested in gaining elo (which of course is totally fine).