Spammers who just blast stuff out won't do it, I'm sure.
But as a counterpoint it literally happened to me to me years ago when I used to use name+<service>@exmaple.com. I got cold emails to 'name+paypal' despite never, ever having used that localpart. I've no doubt it was absolutely targetted and not a hit-and-hope spamblast but it was enough of a wake-up call for me to realise it couldn't really be relied on.
I’ve been doing this for years and have never had any problems with it. It is more likely that generic emails will be generated if you have a domain that is also present as a public website on the internet.
Spammers simply obtain lists of emails through hacking or purchasing them and then spam them, they don't pick a particular address and modify it.