I'm in the US and I went to a small one in my local town. Everyone was 6' apart and masked. There were people there from babies to great-grandparents.
I didn't go to the bigger protest in my nearest city because I am worried about it being impossible to distance there. But I have found it incredibly moving to see thousands of people marching, chanting, lying face down, and peacefully protesting.
These protests are not just about George Floyd. The fact that his murderers have been charged doesn't mean there's nothing left to protest about.
The protests are implicitly a judgement of Trump's presidency and especially his response to the issues of inequality, racism, and poverty.
People keep telling Americans to 'do something about Trump'. There hasn't been much they can do about the fact that he's in power, until they get to vote again, but these protests are their way of letting him know how they feel.
It has been heartening to see similar protests in other countries. It's also been heartening to see the police being exposed and judged for their appalling behaviours, before and during the protests.
For those who want to just write protests off as bored, woke teens going out to be annoying - maybe that's how it is in the UK (although I doubt it, from speaking to friends and family there), but it's certainly not how it is in the US.
There are plenty of perfectly valid reasons not to be protesting during a pandemic, but thank you to those who have protested or provided support in other ways.