Yes, these are estimates. However, the main issue is when estimates are put forward that everyone knows are not realistic.
The true issue is related to the specific question of "Why do devs give estimates that they know are not realistic?"
There are two main answers.
1. More optimistic estimates sound better and you don't have to worry about justifying why it will take longer than people want it to.
2. If there are no consequences for being wrong about estimates, there are no important downsides to giving an unrealistic estimate. Conversely, there are few upsides for giving honest estimates.
How do You know these estimates are not realistic / optimistic?
Do You have access to source code to asses that timeline provided is not realistic?
ad 1)
The true question is why bakers / followers / users ask wrong question.
The only true answer, to the question "when it will be released", is: "it will be released when it's ready" and that's there is to it.
Also they do give You optimistic estimations

.
What You are looking for is
pessimistic estimations - these estimations are more realistic.
Also question to You: what would happen, to the reputation of such dev, when dev says it will take pessimistically 1 month to deliver and after that time don't deliver?
And, as stated in my previous reply, this skill is
very valuable (accurate estimations) and there is a reason why senior devs earn so much $$$ (that's part of their evaluation over the time).
ad 2)
No, You are mistaken, there are
REAL consequences for providing inaccurate estimates, to put it simply
You will get fired.
When You are self employed (be it some random on net using Patreon or game dev studio, well assuming that You are self publishing game dev studio and not relying on $$$ from investors) You don't have to answer to anyone.
Above point brings us to the root of the issue: in Patreon model supporters decide to give support (money) and apparently nowadays money are not a problem and people are willing to wait (spend more money) and not take accountable people that they give money to. As simple as that.