Not all USB Type C ports are same. USB-C port is just a connector shape. An USB-C port belongs to a specific USB version (USB 2.0, 3.0, 3.1, 3.2) and hence has predefined features and capabilities. Only USB-C port with USB 3.1 or above version can stream video.

USB 3.1 or above versions support DP Alt Mode feature. This feature enables them to stream video signal.  You need to confirm if your device's USB Type C port is with USB 3.1 or above version before trying USB Type C to HDMI/VGA applications. To do this, check your device's specifications or consult the manufacturer.

Here is a ready refference list of devices which DO SUPPORT video stream over USB Type C.

Smartphones/Tabs with mobile OS (not a complete list)
Acer Liquid Jade Primo Asus ROG Phone Asus ROG Phone 3 Asus ROG Phone II Asus ROG Phone II Asus ZenFone 3 Ultra Asus ZenFone AR BlackBerry Key2 BQ Aquaris X2 Essential Phone [lower-alpha 1] HP Elite x3 HTC 10 HTC Exodus 1 HTC U Ultra HTC U11 HTC U11+ HTC U12+ HTC U19e Huawei Honor Note 10 Huawei Honor View 20 Huawei Mate 10 Huawei Mate 10 Pro Huawei Mate 20 Huawei Mate 20 Pro Huawei Mate 20 X Huawei Mate X Huawei Mate Xs Huawei P20 Huawei P20 Pro Huawei P30 Huawei P30 Pro Huawei P40 Huawei P40 Pro LG G5/G6/G6+ LG G7/G7+ LG G8 LG Q8 LG V20/V30/V30+/V35/V35+ LG V40/V50/V60 Microsoft Lumia 950 Microsoft Lumia 950 XL OnePlus 7 OnePlus 7 Pro OnePlus 8 OnePlus 8 Pro OPPO R17 Pro Oppo Reno 10x Zoom Oppo Reno 5G PINE64 PinePhone Purism Librem 5 Razer Phone 2 [lower-alpha 1] Razer Phone [lower-alpha 1] Samsung Galaxy A90 5G Samsung Galaxy Fold Samsung Galaxy Note 10 Samsung Galaxy Note 10+ Samsung Galaxy Note 20 Samsung Galaxy Note 20 Ultra Samsung Galaxy Note 8 Samsung Galaxy Note 9 Samsung Galaxy S10/S10+/S10e Samsung Galaxy S20/Ultra/S20+ Samsung Galaxy S8/S8+ Samsung Galaxy S9/S9+ Samsung Galaxy Z Flip Sharp Aquos R5G Smartisan R1 Sony Xperia 1 II Sony Xperia 1/5 Xiaomi Black Shark 2 ZTE Axon 10 Pro ZTE Axon 9 Pro iPad Pro (3rd generation) iPad Pro (4th generation) Samsung Galaxy Tab S4 Samsung Galaxy Tab S5e Samsung Galaxy Tab S6 Samsung Galaxy Tab S7 Asus ZenFone Ares, One Plus 7 or above

Desktops/Laptops/2-in-1 PCs/Tabs with Desktop OS (not a complete list)
Acer Chromebook R13 Acer Nitro 5 Spin Acer Spin 5 Dell Inspiron 13 7000 2-in-1 Dell XPS 13 2-in-1 (9365) Dell XPS 15 2-in-1 (9575) Google Pixelbook HP Spectre x360 HP Zbook Studio x360 Lenovo Yoga 900 Medion Akoya s4403 Acer Switch 5 Cube i7 Book Google Pixel Slate HP Chromebook x2 Huawei MateBook Microsoft Surface Book 2 Microsoft Surface Go Samsung Galaxy TabPro S ASRock Thunderbolt 3 AIC Asus ThunderboltEX 3 Thunderbolt 3 AIC Gigabyte GC-ALPINE RIDGE (rev. 1.0) Gigabyte GC-ALPINE RIDGE (rev. 2.0) Gigabyte GC-TITAN RIDGE (rev. 1.0) MSI Thunderbolt M3 Thunderbolt 3 AIC Sunix UPD2018 Apple iMac (Mid 2017) and newer Apple iMac Pro Asus Zen AiO Asus Chromebox 3 Acer Swift 5 Acer Swift 5 Acer TravelMate P2 Any Chrome OS device incl. Pixel (2015) Apple MacBook (Early 2015) and newer Apple MacBook Air (Late 2018) and newer Apple MacBook Pro (Late 2016) and newer Asus Zenbook 3 Dell Latitude 5490,5400 (2019) Dell Latitude 7373, Dell Inspiron 5570 Dell XPS 12 (9250) Dell XPS 13 (9350, 9360, 9370) Dell XPS 13 2-in-1 (9365) Dell XPS 15 (9550, 9560, 9570) Dell XPS 15 2-in-1 (9575) Gigabyte Aero 15 x9 Gigabyte Aero 15 y9 Gigabyte Aero 15x HP EliteBook Folio G1 HP Envy 13 x360 (2018)[67] HP ProBook 430 G6 HP Spectre 13 HP Zbook HP Zbook Studio Lenovo Legion Y520, Y530, Y7000, Y740 Lenovo ThinkPad A485, A285 Lenovo ThinkPad E485, E585 Lenovo Thinkpad E580 Lenovo Thinkpad T470 Lenovo Thinkpad T470s Lenovo Thinkpad T480 Lenovo Thinkpad T480s Lenovo Thinkpad X1 Carbon (2017) Lenovo Thinkpad X1 Carbon (2018) Lenovo Thinkpad X1 Carbon (2019) Lenovo ThinkPad X270 MSI GS60 6QE Razer Blade Stealth Series (All) Xiaomi Mi Notebook Air 12,5" Xiaomi Mi Notebook Air 13,3" Xiaomi Mi Notebook Pro 15,6 HP Envy 13 x360 (2018)[15] HP Envy 13 x360 (2019)[14] Apple Mac Mini (Late 2018) and newer Zotac PI225 Intel NUC (i3 models) Intel NUC[lower-alpha 1] Acer Chromebook Tab 10

List of devices below which DO NOT SUPPORT video stream over USB Type C (includes models released 2019 or before)
Samsung M series, A series, light version of Galaxy S10, OnePlus 6T or below versions, REDMI, XIAOMI, POCO, REALME,, OPPO, VIVO,LENOVO, LG, MOTOROLA, HTC, NOKIA.