I still have my old Yahoo account in case I still receive something. Truth be told, I only kept it for so long because I always used desktop clients and it never bothered me otherwise. Yahoo had a huge benefit on iOS when it offered push e-mail exclusively right from the start. Yahoo’s web client has never been truly decent, but it’s awful now.
Regarding spam, I’d wager that in most cases, people have simply been negligent. I had two e-mail addresses. One was my very first address and I used it carelessly, so it received lots of spam. The second I used carefully and I have never received spam once (until I was stupid enough to use it for ordering flight tickets, it pushed me over the edge to switch to another provider this time). Yahoo Mail is absolutely great for disposable e-mail addresses, something which iCloud and, to my knowledge, Gmail don’t do nearly as good. I have about 30+ different ones and I have a specific use case for each one. Disposable e-mail addresses are great, because they conceal your true e-mail address while forwarding everything to your main address, unless you choose to break the link. The other benefit is that it helps identifying spammers when you use unique addresses for particular services. It helped me lots of times.
Combating spam is almost always a user fault. Never disclose your address, unless you’re absolutely sure that the recipient is sincere (be extra careful with companies). Use disposable or multiple e-mail addresses for less sincere recipients, so that spammers can be cut off, or use temporary e-mail addresses (e.g. fakeinbox.com) if you don’t want to share your e-mail address at all, but are required to. Don’t put it on a public website or profile (not even a private profile). Don’t click on anything if you think the e-mail is spam and block the loading of remote images if you can (most e-mail clients block remote images automatically once they identify an e-mail as spam), because it’s easy to verify that your e-mail address is still genuine (and hence continue the spamming). You just need a decent strategy.
I don’t recommend Gmail, because it has one of the worst privacy policies you can get. Every e-mail is datamined, every piece of data analysed. Resist the temptation of Google’s ‘free’ e-mail and use something decent. I recommend Protonmail.ch or
Mailbox.org (which I now both use).