While I'm all for the principle and applaud people wanting to take actions like that, and don't doubt their intentions are good I came here to say the same, and one other thing.

Things like these are quite popular and people are for instance all 'for the bees!' while actually not knowing the basics of biology/biodiversity/habitat systems/... and they end up, unknowingly, doing more bad than good. Some of the before/after pictures raise my eyebrows because what was there first was something with a couple of native species and probably (hard to tell because I can't see pesticides being used, but doubt it) a vivid soil life. All providing food/shelter for the native chain of microscopic soil life to larger fauna. The picture after showed all grass/herbs gone and replaced with bare soil and a bunch of pretty-looking flowers. Now, you'd have to count to make sure, but the end result could very well be worse:

- digging is detrimental to soil life. It can straight out kill worms etc, destroys chains of fungi and so on. Yes it comes back, but it should be avoided unless really really needed.

- possible introduction of polluted/foreign particles when planting already grown plants

- many non-local (doesn't even have to be invasive) plants only provide food for generalist species (of which there's ample usually) and/or do not serve as host plants for many other species. I.e. you literally take away the home of fauna and replace it with a fast-food restaurant of which many don't like the taste.

- some of these (in some pictures, most I think) plants only live a year and need to set seed to start again the next year. Not a bad thing per se, but seeds don't thrive just everywhere. Ideally you have to select plants suitable for the specific soil conditions. Otherwise you have flowers one year, and the next year essentially nothing, and after a couple of years you're back to the start. Which could very well be better as I'm explaining, but essentially it's all wasted energy and a small setback which wouldn't have been needed. Altrnatively, people repeat the process because they want the same effect and the cycle starts again.

- possibly minor, but unless you're really lucky, already grown plants come in plastic containers and they have to be moved producing CO2 and so on

There's probably more things I'm forgetting but that's the gist of it. I understand the appeal of a wealth of colors and nice looking flowers but it is usually just not the best thing nature-wise. There are alternatives though, and apart from the really drastic things like 'change this forest to grassland'-style interventions, it's what the local nature conservation teams are doing:

- if you really want to throw seeds around, look around for what grows in the neighbourhood already and source them from there. After figuring out if it's a local species. These days the plant recognition from pictures is getting really good so you don't even have to learn all determmination aspects. Don't dig, just spread them out or stuff them in holes from mice etc.

- if there's patches which are getting wild and covered with only a couple of different species, mow them once or twice each year and get rid of the mowings. Look up when is the best time. Do get rid of the mowings, it's a key aspect to counter the abdundance of nitrous oxide. Takes some years, but grassland managed like that is sort of the summum of biodiversity (not considering other vegetation types that is)

- volunteer with your local nature conservation team, look, talk, learn, apply&spread knowledge

(last note: same goes for the rise in beekeeping which I see locally. Good intentions again, but often without enough thought. The honey bee species used most are generalists and meta-analysis of studies show that on average the effect on native single bees many of which are already endangered, is negative. Some studies showed no effect, none showed a good effect, and most showed a negative one. The local bees just cannot compete with the sudden introduction of a couple of thousand new mouths to feed.)