This message has been deleted.

A T-1000 liquid terminator would be much more difficult to capture and "reprogram" let alone, even feasible (how do you remove his chip?); plus, he was a prototype anyway and was the only one that existed, which Skynet created for the very purpose to send back.
You're right on the money it's impossible to reprogram a T-1000. Its 'chip' as it were is its entire body. Each cell is individually programed on a molecular level to form one mass intelligence (the more you separate from its central mass the 'dumber' it becomes) thus there is nothing to physically reprogram.

makes sense - thanks for taking the time to reply

In the future, all of the machines are created and manufactured by Skynet (In Dark Fate it's Legion), which is the villainous organization. The resistance (John Conner and co) doesn't make machines, they fight a war against them.
In T1, they sent a human soldier; the resistance had no machines to send.
In T2, it is only because John Conner and the resistance captured a T-800 attacking them and reprogrammed it, that there's Arnold the protector.
A T-1000 liquid terminator would be much more difficult to capture and "reprogram" let alone, even feasible (how do you remove his chip?); plus, he was a prototype anyway and was the only one that existed, which Skynet created for the very purpose to send back.
Grace was injured in a war and volunteered to be enhanced by the resistance in the future. The resistance had access to some of Legion's technology to enhance humans to give them a better shot and fighting the machines.
If the resistance could make more powerful machines than Skynet, then Skynet would have never taken over the future in the first place.

Hollyweird.
MAGA! FAFO! Schrodinger's Cat walks into a bar, and doesn't. Dumbocraps: evil people who celebrate murder.

Bad boys are always more exciting than good guys, so it follows that the 'bad' terminators have more charisma and sex appeal than the good ones.

Aren't they upgrades made to improve on the older ones?