I also think that you're doing a great job and I'm frankly a bit puzzled that you don't have more subscribers/views yet.
I'll just suggest that you look deep into YouTube SEO I suppose. You're already spending all this time creating the videos and doing proper SEO is absolutely worth it and it's extremely important, especially for titles that already have a large audience such as the Diablo series .. good SEO will make you stand out from the crowd, otherwise even though your particular video on a particular topic might actually have the better content, someone doing something similar but are utilizing proper SEO will be on top of the search results while yours may not even hit the first page, which seems kinda unfair doesn't it ..
It's VERY important that the titles and descriptions are descriptive, varied, non-static, informative and full of relevant keywords.
And I see that your descriptions are often in Czech - you may be limiting yourself to a Czech audience perhaps. Type clearly in the descriptions what you are doing in the videos, use keywords that people would typically search for and also consider using YouTube Studio's translate function. What you can do is translate the titles and descriptions to reach a larger audience (for example if you translate to English from Czech, you'll now be exposed to the English speaking audience) .. and if you're multilingual (or a bit sneaky) you can translate into even more languages this way .. or even simply use google translate to produce the text and copy paste it (this is the 'sneaky' part). I won't go into more detail, you'll just have to research how to do this but it's a fantastic tool.
I also think that you're doing a great job and I'm frankly a bit puzzled that you don't have more subscribers/views yet.
I'll just suggest that you look deep into YouTube SEO I suppose. You're already spending all this time creating the videos and doing proper SEO is absolutely worth it and it's extremely important, especially for titles that already have a large audience such as the Diablo series .. good SEO will make you stand out from the crowd, otherwise even though your particular video on a particular topic might actually have the better content, someone doing something similar but are utilizing proper SEO will be on top of the search results while yours may not even hit the first page, which seems kinda unfair doesn't it ..
It's VERY important that the titles and descriptions are descriptive, varied, non-static, informative and full of relevant keywords.
And I see that your descriptions are often in Czech - you may be limiting yourself to a Czech audience perhaps. Type clearly in the descriptions what you are doing in the videos, use keywords that people would typically search for and also consider using YouTube Studio's translate function. What you can do is translate the titles and descriptions to reach a larger audience (for example if you translate to English from Czech, you'll now be exposed to the English speaking audience) .. and if you're multilingual (or a bit sneaky) you can translate into even more languages this way .. or even simply use google translate to produce the text and copy paste it (this is the 'sneaky' part). I won't go into more detail, you'll just have to research how to do this but it's a fantastic tool.
Best of luck going forward.