If you wan't to send emails to subscribers, what benefits does an SMTP server have over Gmail?

For free Gmail, the daily limit sending via SMTP is 100 messages per rolling 24 hours. (NOT per day). If you want to send 1000 emails per day, it's impossible. reference

For G Suite, messages per day is 2000, so you can use it if you only send 1000 emails per day. reference

The other reasons that why I don't recommend use Gmail as SMTP are:

• Based on my experience, usually the email go to spam box. (but depends on email content and recipient)
• High risk of suspend/disable your gmail/gsuite account, especially if you want to send blast/broadcast mail.
• TLS setting is required, maybe it will be secured but for some technically reason I don't like it.