This is what happens when the route of the race is decided by sponsorship deals instead of wish to make the race interesting. The race potentially could be a lot more fun to watch Poland doesn't lack roads which could allow for much more selective and competitive GC racing.
As of crashes. The main reason for them is World Tour status, large peloton and sheer number of sprint stages. Many sprinters are desperate for WT win here. GC riders must be in the mix too, because time differences are very small. It's very crowdy. I personally hate when the course in mass sprint stage is too technical but it happens in other races too including the greatest (TdF, Giro, Vuelta). Roundabouts, sharp turns, dangerous road furniture is not exclusive for Poland.