If a defendant in a trial does not testify, is that a strong indicator of guilt?

Or at the very least, is the prosecution more likely to obtain a conviction in such a case?

I'm not involved in any legal cases and I never have been. I ask this question purely out of curiosity. I came to the conclusion that this may be the case due to three high profile cases that I followed, those being Danny Masterson, Jonathan Majors and Karmelo Anthony. In all three of those cases, the defendants did not testify and were subsequently convicted.

For this reason, when I hear about a court case where the defendant does not testify, that is a huge red flag for me. I'm not versed in legal procedures so is this just my own ignorance talking? What reason would a defendant choose not to testify, particularly in cases like the ones I mentioned above in which they are being charged with violent crimes? If you really were innocent, wouldn't you want to get up on that stand and do your damnedest to convince the jury, the judge, whomever?