Thunderbird Mobile will undoubtably bring good things to the table : the arrival of several developers on this ecosystem is going to help a lot and develop public knowledge.
Yet, we cannot hide from the fact that the arrival of Thunderbird, with its fame and the aura surrounding its name, will cause a significant drop in the user count of many open source e-mail apps, developed for decades by relentless small teams of developers who relied solely on users donations to support their work. For example, I've been using FairEmail for years, developed by a single person who thrives to create the best product possible within its own capacities, and still posts an update every one or two days.
Moreover, this will likely cause a dominance of Thunderbird among the market, with its product and technology becoming the norm.
This all goes against the principles of FOSS, that relies on interoperability and decentralization, and while I don't think the Thunderbird Mobile project should be stopped, I believe something must be done to help small e-mail apps and the developers behind them, that will be impacted by the arrival of Thunderbird Mobile on the market.
