In many of the more well known English Bible versions Matthew 28:16-17 has a section heading of The Great Commission.

That heading emphasises the word Go of Matthew 28:19, making it a command to be obeyed and the remainder of the passage gets left aside, but was that the main point of what Jesus was wanting to get across? Am I going off-piste rattling a few 'religious cows' which many hold dear?

Matthew 28:16 ... went to ... where Jesus told them to go.
This was a specific occasion.
Luke in Acts 1:3-4 implies that after His resurrection Jesus appeared at random over a period of time.

Matthew 28:17 They saw him, they worshipped Him, but some doubted.
This is not a matter of doubting the resurrection, they saw him, he ate meals with them (Acts 1:4).
Doubting what ... where is this going, when do we get to boot the Romans out (cfActs 1:6)?
I reckon those were common thoughts during the days following the resurrection.

Matthew 28:18 and 20 contain two encouragements which wrap the go of Matthew 28:19
Matthew 28:18 All authority in heaven and earth has been given to Jesus ... therefore I can go!
Matthew 28:20 Jesus is with us through the Holy Spirit - we have not been left as orphans John 14:15-18

Matthew 28:19 The most frequently used English versions of the Bible begin the verse with the words 'Go' or 'Go therefore' both of which to my mind imply a command to be obeyed / worked out. I don't know its dealt with in other languages or if there are other implications of the Greek. I did find a couple of versions which begin Matthew 28:19 with the words '... wherever you go ...'.

'Wherever you go' makes a lot more sense to me.

In Acts 8:1 we find the first recorded going of the early church - as a result of persecution.
In Matthew 10:23 Jesus gave them (us) instructions about fleeing persecution.
Those who fled preached the word wherever they went Acts 8:4
I reckon it involved marketplace conversations starting something like this 'Why did you move here?'
... I've seen similar with the church meeting in supermarket aisles - Hebrews 10:25

Before the scattering of Acts 8 in Acts 6:1 we read of conflict in the church.
Resolving that conflict led to (but did not cause) a chain of events which culminated in the persecution of Acts 8.
Had the church got into a cosy Jerusalem corner and neglected the nations Jesus spoke of in Matthew 28:19.
Ok, with population migrations people come to us to be discipled ... but we don't have to wait for persecution to go to them.