It's also just harder for small scale direct action to actually shut down major industrial sites related to the energy industry. Destroying a pipeline (by far the easiest form of sabotage because defending hundreds of miles of pipe is impractical) floods oil and gas into the environment. Getting out to offshore rigs and effectively picketing them requires Greenpeace-sized cashflows that grassroots orgs don't have. Big refineries tend to have serious security and not infrequently, connections to much more serious retaliatory measures than the odd angry motorist might offer.
Plus most of the actions taken by groups that do go after these targets are (largely deliberately) ignored by the press. Greenpeace did a major action of that kind earlier this year including multiple outstanding pics and the media barely gave a shit. Same with the climate camp against Ineos. Comparatively it's farily indisputable that JSO gets way more bang for its publicity buck with spectacular actions aimed at events and locations where media interest will be high.
The failure isn't really, then, in identifying the target that'll bring the most attention to the cause and potentially recruit people looking to Do Something, which very much is a strategic need. It's in not being able (willing?) to convert that to the forms of specifically economically disruptive direct action that are no doubt riskier, but also more worrisome to decision makers in Westminster and in boardrooms.