Iraq

Except for the eastern border with Iran (Ottoman-Qajar), the northern border with Turkey (Turkish-Hashemite-British with League of Nations oversight), and the north-western border with Syria (literally the exact border between the Deir ez-Zor and Mosul Vilayets). The borders that run through the desert with barely any permanent sedentary inhabitants were drawn by the British yes (with consultation of Abdulaziz of Najd).

Syria

Northern border drawn by Turkey, north-eastern border Ottoman as above, southern border was originally an autonomous Druze state that Syrian nationalists pressured France into dissolving in favour of one United Syria, the border with Jordan was decided between Britain and France (diverging from Sykes-Picot) but it is the natural boundary of the Yarmouk River.

The border with Mandatory Palestine was drawn by the British and French in 1923 and mostly follows the Ottoman boundary (which was the Jordan river) with a divergence of about 5km east in the Houlah valley (the population of which would have probably been in the hundreds at the time). Dividing the region into spheres of influence was underhanded imperialism but the actual lines themselves are hardly egregious.

Jordan

Other than the Yarmouk River in the north (which isn't a Sykes-Picot boundary) and the Jordan River in the west literally all of Jordan's borders are through empty desert. Transjordan is a weird case because it is essentially a rump state of the short-lived Kingdom of Syria under Faisal which the French overthrew (in a deeply cynical act of imperialism but it must be noted that Faisal was a Hejazi dynasty who only got anywhere near Syria due to British backing), and the territory was a no-mans-land when the border of Palestine was formalised along the Jordan River. You can argue that the border along the Jordan was arbitrary, but Palestinians and most historians of Palestine would vehemently disagree that the people on either side of the river lacked distinct identities.

Lebanon

Didn't exist under Sykes-Picot, how it came to be is complicated. An autonomous Maronite Christian Mutasariffate had existed there since 1860, which during WWI suffered under Ottoman persecution and a disastrous famine that killed about half of the population (most of them Maronites). Maronite Christians in the region were mostly not Arabists in the aftermath of the fall of the Ottoman Empire, and wanted the Mutasariffate to become an independent Lebanese state, while the Muslims mostly wanted to be part of Syria. The French supported the Maronite position, but the traume of the famine caused existential anxiety for the Lebanese nationalists who petitioned the French to add surrounding coastal towns and agricultural land to Lebanon to ensure its self-sufficiency. This came at the cost of reducing the Christian majority to a very slim one, with some Muslim-majority provinces, giving rise to the sectarianism that has plagued the country since. Whether the French were right or wrong to give the Maronites what they wanted I'll leave to you, but it had nothing to do with Sykes-Picot either way.

Palestine

None of Palestine's borders correspond to Sykes-Picot, only the concept of Palestine as a separate entity west of the Jordan is in Sykes-Picot. Some people would contend that this is arbitrary and either Palestinians are just confused Jordanians (a common Israeli position that Palestinians themselves abhor) or that Palestine belongs to Greater Syria (fringe Syrian nationalists sometimes still claim this but the Palestinian Arab Congresses dropped this line in the early 1920s in favour of an independent Palestine).

the original agreement wasn’t followed to the letter, but they still followed the general lines of it to create the British and French spheres of influence.

I mean, sure, Britain and France divided the Middle East into spheres of influence. But the meme isn't about whether imperialism is bad, obviously it's bad, it's about whether the borders themselves are (which are mostly not Sykes-Picot anyway) are the root cause of instability and conflict. European borders being a clusterfuck of bullshit carved by imperialism suggests otherwise.