Choosing the official ranking on HeroesWorld.

I don't think decaying coefficients are necessary; let people remember the heroes of the World.

To ensure people remember the heroes, other methods are needed, not just a rating.
A rating, as such, can reflect:
1. The player's skill;
2. Their result over a specific period of game time.

If we're talking about a rating that reflects a player's skill, then decaying coefficients have a solid justification. And that justification is called "playing form."
The strength of a player in Heroes (sometimes the term "skill" is used) depends, among other things, on their "experience" and the "playing form" they are in. Naturally, a year of not playing in tournaments does not positively affect a player's skill. Even more so, two years.
That's why decaying coefficients are a very good idea.
Resetting the rating aims to calculate the rating as an indicator of a player's skill over a specific period. This also encourages gaming activity. So, the idea is undoubtedly necessary and useful.
A table with two final columns: a seasonal rating (which is reset before the start of the season) and a skill rating (naturally, taking into account decaying coefficients) – that would be a pleasant picture.
By the way, vbn once proposed a complex but very interesting rating system...