I’ll just reply here as a SMB owner - someone who somehow has put it together.
My conclusion :: Mautic works.
My 4.4.0 installation (DigitalOcean) is running my weekly newsletters for 65,000 total readers, registration forms, asset downloads, tracking visitors on a dozen websites, sending out reminder emails, whatsapp and sms messages, adding/removing tags, adding points, etc.
Our entire online events are done using Mautic webforms. I’ve taught my people; it’s easy for them; for the guests; for the clients footing the bill.
I’m sure I could be doing so much more with Mautic. I’m sure my Mautic heroes would tell me that I’m either over or under-extended with my different crons and server configurations, but all-in-all, I get a much clearer sense of who is doing what and automate a message customized to their needs.
Re: my level of expertise? I know enough to be very dangerous. I’ve blown up machines and cried rivers of regret. It happens. It sucks. I tell myself: “I’m too old for this shit.”
Re: email design, I stick to straight html code.
Good luck to you. I feel your pain.