>>87856066GIF is a very bad image format in terms of compression, it's ancient, like 30 years old at this point. What do you want to do? An animation? Even the smallest GIFs are low quality but huge in hard drive space which is the reason something like JPEG for static images, or WEBM for animations is better.
To reduce the size you just have to compress it more, meaning make it blurrier, less detailed, remove frames, scale it down losing pixels, etc. There's no other way. If the GIF becomes too low quality at the size that you want then that's a shame but it's basically impossible to do something better with GIF. At that point turning it into WEBM would be better; you won't improve the quality anymore but your file will be smaller.
In general, the best thing you could do is go back to the original source, get it into WEBM at a high quality, and then you can reduce it further in size while retaining sufficient visual quality.
