Android by itself does not have any ads.
I have had until now 4 Android smartphones, which did not have any ads whatsoever.
Like other posters have said, if you do not buy the phone directly, but subsidized by some carrier, then it might come with crap installed on it.
Of course, currently Google appears to make efforts to make Android worse, so it would not be surprising if ads would appear.
Which Android though? AOSP doesn't have ads. But Samsung phones are full of ads for their own and other's services (McAfee VPN, McAfee security scan, OneDrive, etc.). I heard that Chinese phones are similar. Even Pixel pushes Google One in places.
The primary exceptions are GrapheneOS and Lineage, but it's not like people can buy a phone with them in the store (yet).
> I heard that Chinese phones are similar.
My Xiaomi has no adverts.
But then the Samsung S22 I had before didn't have adverts. Certainly didn't come with McAfee.
> But Samsung phones are full of ads for their own and other's services
I have a Samsung and I've never seen such ads.
The kind of ads they are talking there in the article would be in cheap Chinese phones in the Android world I think.
Moto phones are relatively ad free. There's a few (removable/disableable) apps on it at stock that have ads, the rest is all good.
I've been very happy with the low-end moto phones I've bought, and plan to continue with them until they inevitably get worse.
I've heard their flagships will start coming with GrapheneOS next year. Should be a step in the right direction.