Very easy to say, not so easy to implement
Everyone complains about when we went on lockdown, yet if you look at other timelines, we actually went on lockdown earlier in our timeline than a lot of countries.
For the most part, travel HAS virtually stopped here, I live on the flightpath of major London airports and see about 2 planes a day, usually I step outside and can see at least 6 at any given time, its impossible to stop every single flight though, with medical staff coming and going.
I do agree with you on testing, that should have been made more readily available for everyone from the start, but again, they were in short supply.
This has now changed and you can get a test if you fall into a certain criteria (still having to go out the work etc) Available for all on .Gov if anyone wasn't aware.
Its very easy to sit at home and criticise, even more so when your stuck at home and continue to go over these things, but truth is, the timeline wouldn't have been any different if Joe Bloggs was in charge, because they were following health professionals advice, not just doing what they liked.