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Articulation >>> sculpt. Joints in things not already "supposed" to have them (such as robots) are inherently ugly/inaccurate anyway and it's better to just accept that and try and get the best range possible. Trying too hard to hide the joints usually results in something with inferior range of motion compared to a figure that embraces articulation, but still has a more broken sculpt than a statue, which is what you should be buying if you don't care about posing anyway.
That's not to say companies shouldn't work on engineering solutions to maximize articulation whilst reducing breakup (like Bandai does with their premium-tier Kamen Rider Figuarts range) but if the choice is between articulation and sculpt then 90% of the time articulation should triumph.