HTML 5 and micro markup Schema.org

There is a problem. I'm trying to do SEO for a website. I came across such a thing as micro-markup. Is it necessary at all? probably yes, for snippets and search engine robots.

The fact is that after micro-markup, HTML5 goes to hell according to the W3 validator. How do I find a way out? Are there any easier ways to mark up the data? I saw a glimpse through associative arrays like you can do something. Who faced it? how to find a way out to combine both HTML5 and micro markup Schema.org or other markup.

Just in case, I'll throw an example:

`   <!-- Footer -->
    <footer>
        <div class="container">
            <div class="row">
                <div class="col-sm-6 footer-box wow fadeInUp">
                    <h4>О нас</h4>
                    <div class="footer-box-text">
                        <div itemscope>
                            <p>
                                <span itemprop="name">ДОМИНАНС</span> - экстерьер начинается с нас
                            </p>
                            <p>
                                <b><i>График работы</i></b>:<br>
                                <span itemprop="openingHours" datetime="Mo-Fr, 9:00−18:00"><b>пн-пт</b>: 8:00 -
                                    18:00<br></span>
                                <span itemprop="openingHours" datetime="Sa, 9:00−18:00"><b>сб</b>: 8:00 -
                                    15:00</span>
                            </p>
                        </div>

                        <p><a href="about.html">Подробнее о нас</a></p>
                    </div>
                </div>

                <div class="col-sm-6 footer-box wow fadeInDown">
                    <h4>Свяжитесь с нами</h4>
                    <div class="footer-box-text footer-box-text-contact">
                        <div itemscope>
                            <p><i class="fa fa-map-marker"></i> Адрес: <a
                                    href="https://www.google.com/maps/place/%D0%94%D0%BE%D0%BC%D0%B8%D0%BD%D0%B0%D0%BD%D1%81/@56.1341376,47.295553,16.5z/data=!4m12!1m6!3m5!1s0x0:0x4575d79e5a35c424!2z0JTQvtC80LjQvdCw0L3RgQ!8m2!3d56.1340451!4d47.298796!3m4!1s0x0:0x4575d79e5a35c424!8m2!3d56.1340451!4d47.298796">г.
                                    <span itemprop="addressLocality">Чебоксары</span>, <span
                                        itemprop="streetAddress">Складской проезд д.6, ЧувашГосСнаб, склад/офис
                                        51</span></a></p>
                            <p><i class="fa fa-phone"></i> Phone: <span itemprop="telephone"><a href="tel:+79530102499">
                                        +7(953)010 24 99 </a></span></p>
                            <p><i class="fab fa-vk"></i> VK: <a href="https://vk.com/stroymat21"> Мы ВКонтакте
                                </a></p>
                            <p><i class="fab fa-instagram"></i> Instagram: <a
                                    href="https://www.instagram.com/6818mikhail/">@6818mikhail</a></p>
                            <p><i class="fa fa-envelope"></i> Email: <span itemprop="email"><a
                                        href="mailto:[email protected]?subject=Запрос_c_сайта">[email protected]</a></span>
                            </p>
                        </div>
                    </div>
                </div>
            </div>
            <div class="row">
                <div class="col-sm-12 wow fadeIn">
                    <div class="footer-border"></div>
                </div>
            </div>
            <div class="row">
                <div class="col-sm-7 footer-copyright wow fadeIn">
                    <p>Copyright 2020 All rights reserved. Template by <a
                            href="https://azmind.com/free-bootstrap-themes-templates/">Azmind</a>. Created by <a
                            href="https://vk.com/taramparam">Pavel</a></p>
                </div>
                <div class="col-sm-5 footer-social wow fadeIn">
                    <a href="https://vk.com/stroymat21"><i class="fab fa-vk"></i></a>
                    <a href="https://www.instagram.com/6818mikhail/"><i class="fab fa-instagram"></i></a>
                    <a href="https://wa.me/79530102499"><i class="fab fa-whatsapp"></i></a>
                    <!-- <i href="#"><i class="fa fa-pinterest"></i></a> -->
                </div>
            </div>
        </div>
    </footer>

After the markup, the validator swears at all changes in the code, just the same for this micro-markup