I currently use Fidelity and am interested in their Zero mutual funds because of the zero expense ratio. However, I know these mutual funds are proprietary, and one of the main drawbacks is portability, especially in a taxable brokerage account.
I have also seen other users talk about bonuses for transferring to different brokerages. That said, brokerage transfers seem like a fair amount of work and hassle (speaking from personal experience as I did one for my Roth recently). You have to adjust to a new UI, keep track of each promotion’s rules such as required holding periods, and decide whether it is worth paying transfer fees if you eventually want to move back. I could be wrong, but it seems like most brokerage bonuses are one time and only available to new users.
Because of this, I am wondering whether it makes more sense to invest in the Zero funds or go with ETFs even with a slightly higher expense ratio, in the long-term for a taxable account.