For what it’s worth, there’s already been an extensive discussion about the various pros and cons of eBird. I think it would be best to keep this discussion to the original question of whether @alex2537 should use it rather re-hash that discussion.
@alex2537 I’m not sure any of us can give you a better answer aside from what’s been said - try it out and see if you find it enjoyable and if it enriches your nature explorations.