What I do wrong?

Why nobody buy my content? Am I doing something wrong?

You have 100 videos. You need a lot more before you'll get seen.
Also, I'd suggest using a tripod for locked down shots. Looks like you're using a gimble or something but there is movement which may not be wanted in something that looks like it's a locked shot.

I don't have any sales here either. On another platform, the same portfolio is sold.

Again, 200 in a sea of over 20 million. Different site, different clients.
Shoot more.

I believe in the beginning you need to upload a lot of contents and have patience. I am in this situation, and I do this venture for the long term.

Thanks to all for answers :)

StockMag, Have you sell something?

Your video of lady making incense is really interesting. Surprised that's not sold. Maybe look at your tags. Words I would use would include traditional, crafts, craft making, incense, local, middle age local worker, female, take a look at what the most popular video appear with what tags. If your keywords/tags are minimum or repeat you won't get found.
I only get a sale every 2/3 months but I have few video. Perhaps consider writing a blog and driving traffic to your pond 5 site. It's an effort but can be interesting during lockdown. Everyone on Pond 5 has a personal link from pond5 site, connect it to instagram or Facebook or twitter or reddit or whatever social media you use. Tell everyone to take a look at your work.

Keep trying.