The meaning of Hebrew words is more "flexible" and pliant than in Greek, Latin and English.
The operative word translated, "meaningless", "vanity", "futile", "pointless", etc, (depending on the version) is an attempt to translate the word הֶבֶל (hebel) which literally means, "vapor, breath" (Strongs, NAS). Therefore, a more literal translation might be, "vapid".
For completeness, I have included the BDB entry for this word in the appendix below, showing its versatility - it is used to denote things that are "evanescent, unsubstantial, worthless, vanity", etc.
Thus, I conclude that the various versions that use words like, "meaningless", "vanity", "futile", "pointless", etc, are all equally correct.
APPENDIX - BDB entry for הֶבֶל (hebel)
I. הֶ֫בֶל73 noun masculine vapour, breath (Late Hebrew id., Syriac
id.) figurative vanity (so Late Hebrew, Syriac ) — הָ֑בֶל Ecclesiastes
1:2 +; construct הֲבֵל Ecclesiastes 1:2 (twice in verse); Ecclesiastes
12:8, suffix הֶבְלִי etc. Ecclesiastes 6:12; Ecclesiastes 7:15;
Ecclesiastes 9:9 (twice in verse); plural הֲבָלִים Jeremiah 10:8 +;
construct הַבְלֵי Jeremiah 8:19 +, suffix הַבְלֵיהֶם Deuteronomy 32:21
+; — 1 literal Isaiah 57:13 all of them (the idols) יִשָּׂארֿוּחַ יִקַּח הָ֑בֶל a breath (ᵑ9 aura) will carry away, Proverbs 21:6 the
getting of treasures by a lying tongue is הֶבֶל נִדָּף a vapour driven
away. Elsewhere always
2 figurative of what is evanescent, unsubstantial, worthless, vanity,
as of idols Jeremiah 10:15 = Jeremiah 51:18; Jeremiah 16:19 הֶבֶל
וְאֵין בָּם מוֺעִיל "" (שֶׁקֶרׅ, heathen observances Jeremiah 10:3,
and in phrase הָלַךְ אַחֲרֵי הַהֶבֶל Jeremiah 2:5; 2 Kings 17:15;
Proverbs 13:11 הוֺן מֵהֶבֶל wealth (gotten) out of vanity, (i.e. not
by solid toil, opposed to קֹבֵץ עַל יָד) is minished (but ᵐ5 ᵑ9 Ew
מְבֹהָל, see Proverbs 20:21 Qr), Proverbs 31:30 שֶׁקֶר הַחֵן וְהֶבֶל
הַיֹּ֑פִי, Lamentations 4:17 אֶל עֶזְרָתֵנוּ הֶבֶל to our vain (Dr§
193 n.) help; of life Job 7:16 כִּי הֶבֶל יָמָֽי׃, Psalm 78:33 וַיְכַל
בַּהֶבֶל יְמֵיהֶם consumed their days as (בְּ I:7 d vanity, man Psalm
39:6; Psalm 39:12; Psalm 62:10 הֶבֶל בְּנֵי אָדָם ֗֗֗ הֵמָּה מֵהֶבֶל
יָחַד׃ they are altogether (made) of vanity, Psalm 94:11; Psalm
144:4, especially in Ecclesiastes (31 t. + הֲבֵל הֲבָלִים Ecclesiastes
1:2 (twice in verse); Ecclesiastes 12:8) of the fruitlessness of all
human enterprise and endeavour, Ecclesiastes 1:2 הַכֹּל הֶבֶל,
Ecclesiastes 1:14 הַכֹּל הֶבֶל וּרְעוּת רוּחַ all was vanity and the
pursuit of wind, Ecclesiastes 2:1,14,15 etc., Ecclesiastes 6:4 (of an
abortion) בַּהֶבֶל בָּא i.e. into a lifeless existence, Ecclesiastes
6:11 יֵשׁ דְּבָרִים הַרְבֵּה מַרְבִּים הָ֑בֶל (of discussions leading
to no result), note also the phrases יְמֵי (הֶבְלוֺ, הֶבְלְךָ) הֶבְלִי
Ecclesiastes 7:15; Ecclesiastes 9:9, ׳יְמֵי חַיֵּי ה Ecclesiastes
6:12; Ecclesiastes 9:9; Job 27:12 (see הָבַל), Isaiah 49:4 לְתֹהוּ
וָהֶבֶל for nought and vanity have I spent my strength; as adverb
accusative vainly, to no purpose Isaiah 30:7 הֶבֶל וָרִיק יַעֲזֹ֑רוּ,
Psalm 39:7 אַךְ הֶבֶל יֶהֱמָיוּן they disquiet themselves to no
purpose, Job 9:29: הֶבֶל אִיגָָֽע Job 35:16, with נִחַם to comfort Job
21:34; Zechariah 10:2. Plural הֲבָלִים of false gods, Deuteronomy
32:21 ) כִּעֲסוּנִי בְהַבְלֵיהֶם "" בְּלֹאאֵֿל) 1 Kings 16:13,26;
Jeremiah 8:19 הַבְלֵי נֵכָר "" (בִּפְסִילֵיהֶםׅ, Jeremiah 10:8;
Jeremiah 14:22 הַבְלֵי הַגּוֺיִם, Psalm 31:7 הַשֹּׁמְרִים
הַבְלֵישָֿׁוְא empty vanities Jonah 2:9; in more General sense
Ecclesiastes 1:2 (twice in verse); Ecclesiastes 12:8 הֲבֵל הֲבָלִים,
Ecclesiastes 5:6.