The hadith you've quoted appears in Sahih al-Bukhari in at least 4 chapters in each of them another meaning is more emphasized:
The version compiled in the chapter entitled: the superiority of being poor is preceded (and followed) by other ahadith which may help you understand the meaning more like:
A man passed by Allah's Messenger (ﷺ) and the Prophet (ﷺ) asked a man sitting beside him, "What is your opinion about this (passer-by)?" He replied, "This (passer-by) is from the noble class of people. By Allah, if he should ask for a lady's hand in marriage, he ought to be given her in marriage, and if he intercedes for somebody, his intercession will be accepted. Allah's Messenger (ﷺ) kept quiet, and then another man passed by and Allah's Messenger (ﷺ) asked the same man (his companion) again, "What is your opinion about this (second) one?" He said, "O Allah's Messenger (ﷺ)! This person is one of the poor Muslims. If he should ask a lady's hand in marriage, no-one will accept him, and if he intercedes for somebody, no one will accept his intercession, and if he talks, no-one will listen to his talk." Then Allah's Messenger (ﷺ) said, "This (poor man) is better than such a large number of the first type (i.e. rich men) as to fill the earth." (Sahih al-Bukhari)
We paid a visit to Khabbab who was sick, and he said, "We migrated with the Prophet (ﷺ) for Allah's Sake and our wages became due on Allah. Some of us died without having received anything of the wages, and one of them was Mus'ab bin 'Umar, who was martyred on the day of the battle of Uhud, leaving only one sheet (to shroud him in). If we covered his head with it, his feet became uncovered, and if we covered his feet with it, his head became uncovered. So the Prophet (ﷺ) ordered us to cover his head with it and put some Idhkhir (a kind of grass) over his feet. On the other hand, some of us have had the fruits (of our good deed) and are plucking them (in this world). (Sahih al-Bukhari)
The Prophet (ﷺ) did not eat at a table till he died, and he did not eat a thin nicely baked wheat bread till he died. (Sahih al-Bukhari)
Muslim added the following du'a to the chapter where he compiled this hadit:
" O Allah, I seek refuge in Thee from the withdrawal of Thine blessing and the change of Thine protection (from me) and from the sudden wrath of Thine, and from every displeasure of Thine." (Sahih Muslim)
He also added this narration:
The world is sweet and green (alluring) and verily Allah is going to install you as vicegerent in it in order to see how you act. So avoid the allurement of women: verily, the first trial for the people of Isra'il was caused by women. And in the hadith transmitted on the authority of Ibn Bashshar the words are:" So that He should see how you act." (Sahih Muslim)
If we toke the ahadith above and the hadith we are about to discuss into account we may come to the following conclusion:
To reach Jannah we need to be successful in this life.
however this life offers us many opportunities, challenges and temptations. Those who stay safe from temptations may reach this goal. As Allah says:
Beautified for people is the love of that which they desire - of women and sons, heaped-up sums of gold and silver, fine branded horses, and cattle and tilled land. That is the enjoyment of worldly life, but Allah has with Him the best return. (14)
Say, "Shall I inform you of [something] better than that? For those who fear Allah will be gardens in the presence of their Lord beneath which rivers flow, wherein they abide eternally, and purified spouses and approval from Allah . And Allah is Seeing of [His] servants - (3:14-15)
And among these temptations Allah counted:
Wealth and children are [but] adornment of the worldly life. But the enduring good deeds are better to your Lord for reward and better for [one's] hope. (18:46)
And by logic we know that a rich person would more likely be tempted by his wealth than a poor person who may rather make du'a and have hope and faith in Allah and His gifts. We often witness that rich people are unhappy in this life and they spent their wealth seeking for something a poor person might have: happiness. Some may spent it for good purposes and some for bad purposes. While most poor people are thankful and content with what they have (and try to get more, certainly not all of them in a legal manner) many reach people are tankless, excessive and selfish.
So poor people being a majority in Jannah doesn't exclude that there will be many rich people in there too and a majority doesn't mean that 80-90% of the people of Jannah will be poor people in dunya.
If a person is rich he or she might be tempted more which means if they were able to successfully pass these exams their chances to enter Jannah are very high.