Five decades is a long time.
The way I look at it, it was known that Jesus would not fail, whether there was a chance of it or not. The prophecies are about a Messiah who does not fail. He came to do a job and no doubt it was not a walk over and required all that Jesus had to face the temptations He did and not sin and to not step away from the road that His Father had sent Him to walk.
If He had failed that would have meant that Satan had made God fail and would have won the day and would have shown that God is not righteous.
Death on a cross and separation from His Father in death would have been the hardest part I think and He had to be determined to do it and knowing the outcome, believing what the scriptures said about Him and trusting His Father would not have an easy thing and maybe it would have been even harder, knowing who He was, to humble Himself and not strike back.
Isa 50:6 I offered My back to those who struck Me, and My cheeks to those who tore out My beard. I did not hide My face from scorn and spittle. 7
Because the Lord GOD helps Me, I have not been disgraced; therefore I have set My face like flint, and I know that I will not be put to shame. 8 The One who vindicates Me is near. Who will dare to contend with Me? Let us confront each other! Who has a case against Me? Let him approach Me!…
Luke 9:51 Now it came to pass, when the time had come for Him to be received up, that He steadfastly set His face to go to Jerusalem, 52 and sent messengers before His face. And as they went, they entered a village of the Samaritans, to prepare for Him. 53 But they did not receive Him, because His face was
set for the journey to Jerusalem. 54 And when His disciples James and John saw
this, they said, “Lord, do You want us to command fire to come down from heaven and consume them, just as Elijah did?”
55 But He turned and rebuked them, and said, “You do not know what manner of spirit you are of. 56 For the Son of Man did not come to destroy men’s lives but to save
them.” And they went to another village.