[kehers]

Delivery advantage? I doubt. In the background, some of these tools use AWS SES/Mailgun/Sendgrid. (I know Convertkit use to use Mailgun for sending).

However, it's that they can help with handling the bulk sending properly especially with queuing and scheduling.

Re: link tracking, I believe you can always turn this off. Even for open tracking. Explore the settings and you should find where.