Not sure that that really needs an explanation in an article about FOSS Software projects, but here goes:
Using a closed source messaging system you never know, if 5 years down the line the company who owns you, and who is in control of your communication, decides that they would like to monetize your "contributions" to their system to synergize shareholder smileability, by adding ads to your projects channel.
Or they might want to change their pricing structure so suddenly the barrier to entry to your project is suddenly higher.
Or they get bought by google for their engineering talent and the whole thing ceases to exist.
Or they exclude the bot that you write and depend on a little bit from their network with no explanation given.
Or any other further or not so far fetched scenario in which the owners of the software can do whatever they want without consulting with you, leaving you with little alternatives.
Using a free protocol with free software, if these things happen wrt to the entity writing the code that you rely on or the the hosting of services you rely on, you're still inconvenienced, but these things do not impact you as much, because you're free to continue to use the code without the new sucky modifications, fork if if your able (or rely on some other entity taking over the code) and run the damn service yourself.
Forking and self-hosting aren't always the best solutions, but the more invested you are in a service the better they start to look.
Using a closed source messaging system you never know, if 5 years down the line the company who owns you, and who is in control of your communication, decides that they would like to monetize your "contributions" to their system to synergize shareholder smileability, by adding ads to your projects channel.
Or they might want to change their pricing structure so suddenly the barrier to entry to your project is suddenly higher.
Or they get bought by google for their engineering talent and the whole thing ceases to exist.
Or they exclude the bot that you write and depend on a little bit from their network with no explanation given.
Or any other further or not so far fetched scenario in which the owners of the software can do whatever they want without consulting with you, leaving you with little alternatives.
Using a free protocol with free software, if these things happen wrt to the entity writing the code that you rely on or the the hosting of services you rely on, you're still inconvenienced, but these things do not impact you as much, because you're free to continue to use the code without the new sucky modifications, fork if if your able (or rely on some other entity taking over the code) and run the damn service yourself.
Forking and self-hosting aren't always the best solutions, but the more invested you are in a service the better they start to look.