Since Allah (swt) is the All-Emanating and All-Graceful, and His grace is never-ending, grace calls for Him to continuously create, and He creates everything that deserves to be created. His grace manifests through creating, therefore it is correct to say that His grace necessitates creation.
Allah (swt) can never block His grace, and it is always flowing and reaching everyone and everything it can. This is because Allah (swt) has always existed and has no beginning nor end, therefore His grace has always been and always will be. This grace manifests in every time and era through the creation of a generation, and according to Quranic verses and hadiths, this current generation of humans are the continuation of one who was created from water and dirt.
Under verse 15 of surah Qaf, Tafsir Safi says: “Were We exhausted by the first creation [making us unable of making another creation]? Rather they are in doubt about a new creation”.
There is a hadith by Imam Baqir (as) that is the answer to this exact question. He was asked about the creation of others after this race of humans, and the imam replied: “When Allah (swt) ends the lives of the people and this world, and takes those who deserve heaven to heaven and those who deserve hell to hell, He will create a new world with new people, without them being born from a father and mother; monotheists who will worship Him. He will create a new abode for them other than this world to inhabit and a sky in which they will take refuge under. Do you really think that Allah (swt) hasn’t created anyone but you the children of Adam? Indeed Allah (swt) has created a million worlds and a million peoples...” According to the beginning of this hadith, after the end of this world, creation will not cease, on the contrary, creation of new people will continue with a new world and new sky.
1- The physical creation of Prophet Adam, Question 506 (website: 547).
2- The Quran and the creation of man, Question 731 (website: 911).
3- The purpose of creation, Question 76 (website: 319).
4- Adam, the eighth generation of humans, Question 5901 (website: 6471).
 “أَ فَعَیینا بِالْخَلْقِ الْأَوَّلِ بَلْ هُمْ فی لَبْسٍ مِنْ خَلْقٍ جَدیدٍ”
 Sheikh Saduq, Khisal, vol. 2, pg. 652; Muhsin Feyz Kashani,Tafsir
afi, vol. 5, pg. 60 “انه سئل هذه الآیة فقال تأویل ذالک، ان الله تعالی اذا افنی هذا الخلق و هذه العالم و سکن اهل الجنة الجنة و اهل النار النار جدد الله عالماً غیر هذا العالم و جدد خلقاٌ من غیر فحولة و لا اناث یعبدونه و یوحدونه و خلق لهم ارضاٌ غیر هذه الارض تحملهم و سماء غیر هذه السماء تظلهم، لعلک تری ان الله انها خلق هذا العالم الواحد، تری ان الله لم یخلق بشراً غیرکم، بلی و الله لقد خلق الف الف عالم و الف الف آدم، ...”