Perhaps not for most industries, although presumably this is a relative scale and those working with tight margins might disagree. But as you point out yourself, the tariffs do vary significantly by industry and can be much higher in some cases.
One could equally point out that average tariffs under the WTO arrangements are also only a small percentage, which is falling, but can also be significantly higher in some sectors. Apparently quite a few people are concerned that the harder possible varieties of Brexit would cause trade with the EU to suffer severely because of those tariffs.
My personal view is that the tariffs look like a relatively small barrier overall, and while we should be careful about the sectors that could be hit much harder, it's the non-tariff barriers where we should be concentrating most of our attention.
https://fullfact.org/europe/uk-leaving-eu-trade/
" EU’s trade weighted average MFN tariff was 2.3% for non-agricultural products. This is an average figure and tariffs on some individual products are much higher, especially on agricultural goods. The EU tariff on cars, for example, is 10%."
Is 2.3% really worthy of being called "high"? Many of these tariffs are reciprocal anyway.
The customs union allows containers to unload at Rotterdam and perform customs clearance once there, in a giant dedicated facility, before being transshipped to wherever they are destined for.