I agree with most of your comment, except for this:

Why don’t they target the people that are actually causing the problems?

For one, they do. But it gets much less coverage, so it may well be you never heard of such an action. Media rather reports on stories which affect many people, and more importantly, which are likely to generate outrage, clicks and shares.

Another reason is, it's much harder. To block a public bridge is much easier than preventing high ranking officials to get from A to B. In case of the bridge, all the information is openly available. You can even visit the location in preparation, no one will bother you. If you instead want to block a minister from entering a building, there is likely more than one way, and security in place to keep you out but allow them free passage.

Finally, resources are limited. An acivist group likely has no more than a few dozen people available, often less than a dozen. There's always more to do, and never enough volunteers to help out. So you naturally have to work efficiently, especially with costly activities which might get people detained for prolonged periods.

What good is it if you block a CEO from using his private jet, but end up in prison for months, and no one notices anyways because the news don't cover your story, and the CEO only got delayed for 10 minutes anyways because he can use the back entrance? Yes, you could also block the back entrance, but then you need more people for the same goal.

We can complain how it is unfair to hold the public hostage. But this seems to be the only kind of action which consistently gets good coverage, and forces a reaction (unlike demonstrations which can just be ignored, and thus are), with the available means.

Still I lost hope this approach works as intended. I think the strategy depended on the public to solidarize with the activists, due to their just cause and the urgency of the situation. Instead, many people (or is their number an exaggeration of the media?) solidarize with the state removing the obstruction by violent means.

This whole episode could be long over if people demanded their leaders to do what's necessary. Instead, the people "chose" to condone their lack of action. Climate activists have no where to go though. It's not a sport or leisure activity, after all. Changing for less efficient methods or to step down is not an option.